OCTOBER 2017 GNEISS TIMES Wickenburg Gem & Mineral Society, Inc
VOLUME 49, Issue 7 OCTOBER 2017 GNEISS TIMES Wickenburg Gem & Mineral Society, Inc. P.O. Box 20375, Wickenburg, Arizona, 85358 E-Mail — [email protected] www.wickenburggms.org The purpose of this organization shall be to educate and to provide fellowship for people interested in rocks and minerals; to foster love and appreciation of minerals, rocks, gems, and the Earth. Membership shall be open to all interested people.
CAUSES OF COLOR IN MINERALS Color is probably the first thing we notice when we see a mineral specimen. But what causes those colors and their variations? We often simply say A graduate of Wickenburg High School, Everett is that the presence of a particular element (either attending Estrella Community College, and will integral to the mineral’s composition, or as in transfer to ASU in the future. impurity) imparts a particular color. And basically that is true, however……... ELECTIONS COMING --
In fact, Beryl, Quartz, and Tourmaline are examples DUTIES OF CLUB OFFICERS of minerals that would be clear, if not for impurities. The club will be holding election of officers in December. The nominating committee will be But technically, color is caused by the absorption of preparing a ballot of nominees. Several of these wavelengths of visible light*, so that the light positions are open. Anyone willing to fill an opening reflected back to our eyes is deficient in the please contact Craig or Debbie. The vitality of our wavelength absorbed. There are five main club is dependent on the participation of the categories under which this occurs: metal ions in members! The club was founded in the early 1970’s the chemical formula or as impurity, intervalence and the current membership is 127. Please consider charge transfer, radiation, band gaps, and physical lending your talents. effects (diffraction, dispersion, interference, This article is from the Wickenburg Gem and Mineral scattering). Additionally, heat could be entered as Society bylaws: another catalyst of color change -- in association
with other processes. And of course, often it is a combination of these processes that determines the ARTICLE VII color and/or depth of color. Plus the light source is DUTIES a factor, as it determines what wavelengths of light are available. I’m afraid nothing is ever simple! Section 1: The President shall preside at all business meetings of the group. A mineral’s color is dependent on Section 2: The Vice President shall assume the • Interaction of light with atoms duties of the president when the president is absent. • Wavelengths of light available
• Composition of the mineral • Bonding strengths within the mineral Duties continued on page 2…. • Integrity of the crystal lattice Inside this Issue
* Visible white light is composed of many wavelengths of light Causes of Color in Minerals 1, 4-15 within the visible spectrum -- red, orange, yellow, green, blue, 2017 WGMS Gem and Mineral Show & Club News 2 violet (ROYGBV). And each wavelength represents a different energy level. Officer Duties 1,3-4
Scholarship Winner Announcement 1
Color continued on page 3….. Show list, Field Trips, Club Information 16
show. the
grams 4.8
grams 6 Coulter at the next meeting or buy at at buy or meeting next the at Coulter
whole string of tickets!) See Karen Karen See tickets!) of string whole
Buy a nugget raffle ticket (or a a (or ticket raffle nugget a Buy
vendors the support and show the Attend
Contest Rock Best the Enter
Lend some time to the Kid the to time some Lend Room Fluorescent & Table s ’
Help set up on Friday, and take down on Sunday on down take and Friday, on up set Help
auction silent the or items Donate
prizes door for items Donate
Please consider VOLUNTEERING! consider Please can. we as much as
s show, and it is important that we all participate participate all we that important is it and show, s ’ club our is This
Hassayampa Elementary School School Elementary Hassayampa
4 4 - 9 Sun 5; - 9 Sat
Nov 25 & 26, 2017 2017 26, & 25 Nov
WGMS ROCK & MINERAL SHOW SHOW MINERAL & ROCK WGMS
REMEMBER:
meeting! the before
Elephant Gift Exchange Gift Elephant
share a meal with your fellow members, members, fellow your with meal a share
Potluck and White White and Potluck See you at 6:00 pm on November 10th to to 10th November on pm 6:00 at you See
Dictionary Webster - Merriam
6:00 pm 6:00
bring food to share to food bring
friday, december 1 december friday,
meal to which people people which to meal
and save the date the save and
potluck: a communal communal a potluck:
BREAK OUT THE HOLIDAY DUDS DUDS HOLIDAY THE OUT BREAK
2017 OCTOBER
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VOLUME 49, Issue 7 Issue 49, VOLUME
Celestian Sue by Photos
…. Continued
annual Best Rock Contest. Contest. Rock Best annual 4 the in found ever you
th
the hourly door prize drawings. Enter your best rock rock best your Enter drawings. prize door hourly the
the Silent auction, along with prizes to give away in in away give to prizes with along auction, Silent the
pendent for the show raffle. Rocks will be needed for for needed be will Rocks raffle. show the for pendent
and Margaret D for donating a beautiful silver silver beautiful a donating for D Margaret and
Karen will be selling tickets. Also thanks to George George to thanks Also tickets. selling be will Karen
s raffle. Bill and and Bill raffle. s ’ year this for nuggets gold 2 have
preserved. superbly
to Robbie and Ken for donating their nugget. We will will We nugget. their donating for Ken and Robbie to
delicate biota was was biota delicate
sale, door prize ticket and UV light display. Thanks Thanks display. light UV and ticket prize door sale,
oxygen water water oxygen - low
table, silent auction, best rock contest, raffle ticket ticket raffle contest, rock best auction, silent table,
deep. In the cold, cold, the In deep.
s s ’ Kid with help to and cases, show 4 the for available lake, up to 500 feet feet 500 to up lake,
udy h 26 the Sunday 4PM: Signup sheets sheets Signup 4PM: - 10AM
river, forming a a forming river,
th
5PM and and 5PM - 9AM 25 November Saturday Show Club basalts dammed a a dammed basalts
th
Columbia Plateau Plateau Columbia
month. next Details desert. the in
flows of the the of flows
Craig will be taking a group out for Thanksgiving Day Day Thanksgiving for out group a taking be will Craig
million years ago, ago, years million
outings. club for insurance 15.5 15.5 - 15 ID. Clarkia,
Steve H will be inquiring about Helicopter rescue rescue Helicopter about inquiring be will H Steve sediments, near near sediments,
Miocene lake lake Miocene - mid
meeting. each at
Fossil Bowl, in the the in Bowl, Fossil
making the coffee and setting up the potluck dinners dinners potluck the up setting and coffee the making
collected it at the the at it collected
tickets, along with Roxy and Don U who will be be will who U Don and Roxy with along tickets,
sp.). Sue & Stan Stan & Sue sp.).
volunteered to greet people and hand out door prize prize door out hand and people greet to volunteered
Beech leaf (Fagus (Fagus leaf Beech
There is also a need for committee chairs. Karen C C Karen chairs. committee for need a also is There
This is probably a a probably is This
put together a summary of officers duties. officers of summary a together put
4…. page on continued Duties
newsletter. Debbie will review the club by club the review will Debbie newsletter. laws and and laws -
approval. for membership the to recommendations responsibilities of each office be presented in the the in presented be office each of responsibilities
s s ’ committee the presenting and applicants evaluating up in December Stan requested a description of of description a requested Stan December in up
updating and distributing scholarship applications, applications, scholarship distributing and updating returning to AZ for the winter. With elections coming coming elections With winter. the for AZ to returning
coordinate necessary actions such as preparing, preparing, as such actions necessary coordinate secretary position is also open, Judi Z will not be be not will Z Judi open, also is position secretary
The Scholarship Chair shall shall Chair Scholarship The 12: Section running for president of the club next year. The The year. next club the of president for running
New Business: Craig has announced he will not be be not will he announced has Craig Business: New computer. and machine photocopy
also responsible for the housing and upkeep of the the of upkeep and housing the for responsible also College.
monthly newsletters for the meeting months and is is and months meeting the for newsletters monthly student account at the Estrella Mountain Community Community Mountain Estrella the at account student
The Editor shall publish and distribute distribute and publish shall Editor The 11: Section scholarship recipient. $3,000 was deposited into his his into deposited was $3,000 recipient. scholarship
Unfinished Business: Everett Solper was the 2017 2017 the was Solper Everett Business: Unfinished help promote the WOWW show. WOWW the promote help
means available to publicize the Clubs activities and and activities Clubs the publicize to available means
introduced. were members new and Guests Debbie.
The Publicity Chair shall use all all use shall Chair Publicity The 10: Section
The treasurer report was approved as presented by by presented as approved was report treasurer The
The minutes for the May meeting were not available. available. not were meeting May the for minutes The 1 page from continued ...Duties
Eclipse.
Keiser Debbie
presented a program on the August 21, 2017 Total Total 2017 21, August the on program a presented
Respectively submitted, submitted, Respectively
luck dinner Stan C C Stan dinner luck - pot a After said. was allegiance
with 31 people in attendance. The pledge of of pledge The attendance. in people 31 with 6PM. at starting
The meeting was called to order by Debbie Keiser Keiser Debbie by order to called was meeting The Next meeting will be Nov. 10 with a potluck dinner dinner potluck a with 10 Nov. be will meeting Next
first door prize winner was Erma R. Erma was winner prize door first
October 13, 2017 13, October — Minutes Meeting Show and tell prize was won by George S and the the and S George by won was prize tell and Show
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Diagram by Susan Celestian Susan by Diagram
each other out, so that the atom has no net charge. charge. net no has atom the that so out, other each
Note that the negative and positive charges balance balance charges positive and negative the that Note
and the yellow balls are electrons (negative charge). charge). (negative electrons are balls yellow the and
meetings. from absent
charge), the blue balls are protons (positive charge), charge), (positive protons are balls blue the charge),
contact or send cards to members who are ill and and ill are who members to cards send or contact
In this diagram, the green balls are neutrons (no (no neutrons are balls green the diagram, this In
the door prize drawing at each meeting, and and meeting, each at drawing prize door the
charged electrons. electrons. charged - negatively of orbits by surrounded
sign up persons attending each meeting, conduct conduct meeting, each attending persons up sign
charged nucleus, nucleus, charged - positively a of composed is atom
membership list, encourage membership, greet and and greet membership, encourage list, membership The The Atom an of Schematic Idealized 1 FIGURE
Section 9: Section The Membership Chair shall keep the the keep shall Chair Membership The
required. as functions other such and dismantling
-
-
up and and up - set funds, rosters, duty cases, show
-
all the necessary arrangements regarding dealers, dealers, regarding arrangements necessary the all -
Chairman shall make make shall Chairman - Co the of assistance the with -
- and Fair Arts and Gem Wickenburg WOWW the for -
The Show Chair shall be responsible responsible be shall Chair Show The 8: Section
- -
-
- present. members of approval on payment
same shall be turned over to the treasurer for for treasurer the to over turned be shall same -
shall purchase supplies as needed. All bills for for bills All needed. as supplies purchase shall
+
-
-
- + charge of refreshments served at meetings and and meetings at served refreshments of charge
- +
+ +
The Refreshment Chair shall have have shall Chair Refreshment The 7: Section
- +28
location.
-
-
- choice of material and and material of choice ’ members the ascertaining
-
and conduct tours for field material after after material field for tours conduct and
- - The Field Trip Chair shall arrange arrange shall Chair Trip Field The 6: Section
-
members.
-
speakers and educational programs as directed by by directed as programs educational and speakers
-
-
- program part of each meeting and shall arrange for for arrange shall and meeting each of part program
The Program Chair shall conduct the the conduct shall Chair Program The 5: Section
nucleus.) the
varies, depending on the bonding type and pull of of pull and type bonding the on depending varies, budget.
amount of energy it takes to dislodge an electron electron an dislodge to takes it energy of amount meeting and assist in development of the annual annual the of development in assist and meeting
they absorb discreet packages of energy. And the the And energy. of packages discreet absorb they bills as authorized, give a financial report at each each at report financial a give authorized, as bills
within these orbits that electrons will stay, unless unless stay, will electrons that orbits these within and funds and issue receipts for same, shall pay pay shall same, for receipts issue and funds and
cloverleaf pathways around the nucleus). It is is It nucleus). the around pathways cloverleaf The Treasurer shall receive all dues dues all receive shall Treasurer The 4: Section
electrons move in spherical, dumbbell, and and dumbbell, spherical, in move electrons
date.
simplified conceptualization, as in actuality actuality in as conceptualization, simplified
help of the President and keep the Bylaws up to to up Bylaws the keep and President the of help
shells/orbits (Figure 1). (This is a very very a is (This 1). (Figure shells/orbits - sub
shall also attend to all correspondence with the the with correspondence all to attend also shall
by roughly concentric energy shells or orbits, and and orbits, or shells energy concentric roughly by
time. The Secretary Secretary The time. reasonable any at member
One can visualize atoms as a nucleus, surrounded surrounded nucleus, a as atoms visualize can One
records shall be available for inspection by any any by inspection for available be shall records
IONS METAL the business conducted at each meeting. meeting. each at conducted business the These These
The Secretary shall keep a record of of record a keep shall Secretary The 3: Section
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Celestian Stan by Photos
atoms.
in the outer orbits of the the of orbits outer the in
C
energy to excite electrons electrons excite to energy
4. Figure structure.
it takes different levels of of levels different takes it
impurities, included in the mineral mineral the in included impurities,
strengths. Consequently, Consequently, strengths.
are all the result of chromium ions as as ions chromium of result the all are
their electrons with varying varying with electrons their
red of Alexandrite Alexandrite of red - purplish and Emerald, of
three minerals hold onto onto hold minerals three
colors. However, the red of Ruby, green green Ruby, of red the However, colors. the atomic structures of the the of structures atomic the
Those are 3 minerals with wildly different different wildly with minerals 3 are Those by the same ion, because because ion, same the by
Ruby, Emerald, and Alexandrite. Wow! Wow! Alexandrite. and Emerald, Ruby, Different colors are caused caused are colors Different
causing impurity in in impurity causing - color the is It example. B
(C). Alexandrite
, for for , Cr Take electrons. the excite
red of of red - purplish the 3+
strengths will effect the energy needed to to needed energy the effect will strengths green of Emerald (B), and and (B), Emerald of green
given ion, since the structure and bonding bonding and structure the since ion, given for the red of Ruby (A), the the (A), Ruby of red the for
determine what color is produced by a a by produced is color what determine ) are responsible responsible are ) (Cr ions
3+
Impurities of chromium chromium of Impurities The atomic structure of minerals will help to to help will minerals of structure atomic The
Alexandrite and Emerald
3. Figure molecule). oxide
FIGURE 4 Ruby, Ruby, 4 FIGURE
s color is due to VO to due is color s ’ Cavansite (vanadium (vanadium
2+ 2+
2. Figure Malachite. of green
A
characteristic blue color of Azurite and the the and Azurite of color blue characteristic
azurite and malachite, results in the the in results malachite, and azurite
intrinsic to the chemical compositions of of compositions chemical the to intrinsic
India India Photo by Stan Celestian Stan by Photo
For example, the presence of copper, copper, of presence the example, For Pune District, Maharashtra, Maharashtra, District, Pune
Wagholi Quarry, Wagholi, Wagholi, Quarry, Wagholi
color. particular a is result the and FIGURE 3 Cavansite Cavansite 3 FIGURE
that change is subtracted from those of visible light, light, visible of those from subtracted is change that
higher energy levels. The wavelength that effected effected that wavelength The levels. energy higher
may absorb some energy, and be kicked into into kicked be and energy, some absorb may
periodic table, plus a few others such as uranium) uranium) as such others few a plus table, periodic
Sc through Zn, in the first row of the the of row first the in Zn, through Sc -- metals
outer orbits of metals (usually one of the transition transition the of one (usually metals of orbits outer
Celestian Stan When light strikes some minerals, electrons in the the in electrons minerals, some strikes light When
colors. colors. Photos by by Photos wont to absorb energy, in search of a pairing. pairing. a of search in energy, absorb to wont
characteristics characteristics
with visible light, and lone, unpaired electrons are are electrons unpaired lone, and light, visible with
thank for their very very their for thank
the nucleus that they are vulnerable to interaction interaction to vulnerable are they that nucleus the
copper ions to to ions copper
outer orbital, are far enough from the influence of of influence the from enough far are orbital, outer
and malachite have have malachite and
orbit the nucleus in these shells or orbits. Those in in Those orbits. or shells these in nucleus the orbit
carbonates, azurite azurite carbonates,
-- pairs in typically -- Electrons charges. negative Both copper copper Both
atom is neutral, with a balance of positive and and positive of balance a with neutral, is atom and Malachite Malachite and
charge). The ideal ideal The charge). - ( electrons by balanced is FIGURE 2 Azurite Azurite 2 FIGURE
protons (+ charge) and neutrons (no charge). This This charge). (no neutrons and charge) (+ protons
charged nucleus is composed of of composed is nucleus charged - positively The
: continued Ions Metal
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Namibia Massif,
Sandamap Farm, Kariib District, Erongo Erongo District, Kariib Farm, Sandamap Purpurite
Argentina
Capilitas Mine, Mine, Capilitas
Rhodochrosite, Rhodochrosite,
Namibia
District, Erongo Massif, Massif, Erongo District,
Schorl, Omaruru Omaruru Schorl,
Brazil Gerais, Minas
Elbaite, Pederneira Mine, Mine, Pederneira Elbaite, Tourmaline black Ti Mn, Fe,
Tourmaline green V & Cr
3+ 3+
Paraiba Elbaite (tourmaline) Elbaite Paraiba Cu
2+
AZ Co., Graham Carlos, San
e Cblin act, le Spinel blue Calcite, Cobaltian red Co Forsterite (olivine), (olivine), Forsterite
2+ 2+
Diopside
yellow Plagioclase, bright orange orange bright Plagioclase, yellow
Celestian Stan
green Andradite (garnet), (garnet), Andradite green - yellow
ea in ion. metal Images by by Images
pale purple Strengite & Coquimbite, Coquimbite, & Strengite purple pale Fe
3+ 3+ atom of a transition transition a of atom
an impurity or integral integral or impurity an
(tourmaline)
this page are colored by by colored are page this
Phosphophyllite, blue Elbaite Elbaite blue Phosphophyllite,
All the minerals on on minerals the All Ions
green - bluish (olivine),
Determined by Metal Metal by Determined
green Forsterite Forsterite green - yellow garnet,
FIGURE 5 Minerals Minerals 5 FIGURE
raspberry red Eudialyte, red Pyrope Pyrope red Eudialyte, red raspberry Fe
2+ 2+
Willemite green - yellow
pink Rhodonite, red Rhodochrosite, Rhodochrosite, red Rhodonite, pink Graham Co.,AZ Graham San Reservation, Carlos Butte, (garnet), StanleyAndradite Mn
2+ 2+
Purpurite
red Tourmaline, Tourmaline, red - pink Tremolite,
red Beryl, green Andalusite, violet violet Andalusite, green Beryl, red Mn 3+ 3+
5): (Figure colors different
Other examples of a given ion producing producing ion given a of examples Other
continued: Ions Metal
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5…. page on continued Eclipse
Celestian Stan by Photos red of variation
Mine in England, actually fluoresces in Sunlight. Sunlight. in fluoresces actually England, in Mine
some variation of green to some some to green of variation some
appears reddish/purplish. reddish/purplish. appears Fluorite from the Rogerley Rogerley the from Fluorite B
• Some Garnets: most exhibit exhibit most Garnets: Some
incandescent light (which is deficient in green and blue) it it blue) and green in deficient is (which light incandescent
blue/purple/red human eye is most sensitive to green; while in in while green; to sensitive most is eye human
• Zoisite (Tanzanite): (Tanzanite): Zoisite because in the presence of the full light spectrum, the the spectrum, light full the of presence the in because
Alexandrite appears green in daylight, daylight, in green appears Alexandrite A Variation
7) (Figure
FIGURE 7 Pleochroism Due to Light Source Source Light to Due Pleochroism 7 FIGURE
dark red/orange/green red/orange/green dark
• Chrysoberyl (Alexandrite): (Alexandrite): Chrysoberyl
Sunlight
Left: Left: -- above are: variation source light to due
light; light;
controlled displays listed listed displays controlled - structure the
descent descent
to distinguish it from from it distinguish to ’ change color ‘ called
Incan-
often often -- pleochroism of examples Some
Above: Above:
red red/dark
pale yellow/dark yellow; light light yellow; yellow/dark pale
green; green; - green/yellow - green/brown
B
- blue blue; blue/dark light
• Tourmaline: pale purple/purple; purple/purple; pale Tourmaline:
A
purple/clear/pink
• (Kunzite): Spodumene
• Hypersthene: purple/orange Hypersthene:
Photos by Stan Celestian Stan by Photos
yellow yellow/pale
appear in different colors, or intensities of color. color. of intensities or colors, different in appear
brown/orange; brown/orange; - yellow
the atomic structure, both Kunzite (A) and Andalusite (B) (B) Andalusite and (A) Kunzite both structure, atomic the
• Corundum: purple/orange; purple/orange; Corundum:
When viewed along different directions within within directions different along viewed When Control
FIGURE 6 Pleochroism Due to Atomic Structure Structure Atomic to Due Pleochroism 6 FIGURE • Beryl (Emerald): green/blue (Emerald): Beryl green -
reddish and olive, 6) (Figure red/purple
varies from brownish, brownish, from varies
• Andalusite: green brown/dark brown/dark green Andalusite:
See how the color color the how See
are: control structure atomic
Some examples of pleochroism due to to due pleochroism of examples Some
variations. these candlelight, and fluorescent lights that induce induce that lights fluorescent and candlelight,
Kunzite will dominate. Typically it is sunlight, sunlight, is it Typically dominate. will
dominate; if it is deficient in blue, then reds reds then blue, in deficient is it if dominate;
will blues then red, in deficient is source the
available from the light source. For example, example, For source. light the from available
A B The other depends on the wavelengths wavelengths the on depends other The (B)
light.
of absorption the on influence
structure of these minerals exerts a strong strong a exerts minerals these of structure
Rogerly Mine, in England (Figure 7) (Figure England in Mine, Rogerly
views the mineral. In other words, the atomic atomic the words, other In mineral. the views
• Fluorite, especially that from the the from that especially Fluorite,
One depends on in what direction one one direction what in on depends One (A)
green/pink or reddish or green/pink violet -
reasons. of couple a for • A rare Sapphire: blue/purple or or blue/purple Sapphire: rare A
to exhibit different colors. This can happen happen can This colors. different exhibit to
yellow//ginger
Pleochroism is the property of some minerals minerals some of property the is Pleochroism
raspberry/champagne/canary raspberry/champagne/canary
green/sage green/pink to to green/pink green/sage
: continued Ions Metal
• Diaspore (Zultanite): khaki khaki (Zultanite): Diaspore
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color. lavender for account
n ae te Fe the Jade, In IVCT may may IVCT Fe -
+ 3+ 2+
(Figure 9) (Figure
depends in Intervalence Charge Transfer. Charge Intervalence in depends
With Beryl, the result is aquamarine. aquamarine. is result the Beryl, With
See Figure 9 for images of minerals whose color color whose minerals of images for 9 Figure See
9) (Figure
green, turning blue as IVCT occurs. occurs. IVCT as blue turning green,
found in Vivianite. It is naturally pale pale naturally is It Vivianite. in found
IVCT can be be can IVCT Fe - Fe of example An
3+ 3+ 2+
Celestian Susan by Diagram
spectrum. the of part blue the in show to mineral the causes light, red of
respective ions reside in the atomic lattice, of a given mineral.) That absorption absorption That mineral.) given a of lattice, atomic the in reside ions respective
do not denote any particular site, they are just hypothetical sites, where the the where sites, hypothetical just are they site, particular any denote not do
and as the original Fe original the as and . (Positions A and B B and A (Positions . Fe becomes it electron an gains
2+ 3+
from Fe from , , Fe to altered is it electron, an loses Fe original the As . Fe to
3+ 2+ 2+ 3+
energy, from the red portion of the light spectrum, causes an electron to jump jump to electron an causes spectrum, light the of portion red the from energy,
IUE Fe 8 FIGURE The absorption of of absorption The Transfer Charge Intervalence Fe -
+3 +3 +2
(position B) B) (position Fe - A) (position Fe (position B) B) (position Fe - A) (position Fe
2+ 2+ 3+ 3+ 3+ 2+ Wavelengths Red
of Absorption
brown green. or blue typically
- yellow to Yellow Ti - Mn of red wavelengths of light, so the mineral is is mineral the so light, of wavelengths red of
4+ 2+
green brown, (Figure 8). This usually results from the absorption absorption the from results usually This 8). (Figure
- orange to Amber Ti - Fe eoe Fe becomes Fe the and , Fe becomes Fe
4+ 2+
3+ 3+ 3+ 2+ 2+
, when an electron transfer occurs the the occurs transfer electron an when , Fe and Fe
3+, 2+
Black Fe - Fe metal ions. In the case of of case the In ions. metal - non and metal between
3+ 2+
with different charges, or as described below below described as or charges, different with --
impurities):
an electron transfers between adjacent metal ions ions metal adjacent between transfers electron an
often in combination with metal ions as as ions metal with combination in often Intervalence charge transfer (IVCT) occurs when when occurs (IVCT) transfer charge Intervalence
(sometimes activated by radiation, and and radiation, by activated (sometimes
transfer. this in participate that
be accounted for by IVCT Interactions Interactions IVCT by for accounted be
Of course, there are many other ions ions other many are there course, Of Ti and Ti
4+ 4+ 3+ Some of the many colors of tourmaline can can tourmaline of colors many the of Some
-- titanium is pair ion element common Another
. . Fe and Fe are iron of ions common example,
9) (Figure color. blue
3+ 2+
charged). For For charged). - negatively is it (and protons
a triad of sulfur ions that cause its bright bright its cause that ions sulfur of triad a
charged), or more electrons than than electrons more or charged), - positively is atom
In the case of Lazurite, it is IVCT between between IVCT is it Lazurite, of case the In
are either more protons than electrons (and the the (and electrons than protons more either are
Ions are atoms with a charge. In other words, there there words, other In charge. a with atoms are Ions to create the blue colors. (Figure 9) (Figure colors. blue the create to
Ti - Fe and Fe IVCT come into play, play, into come IVCT
TRANSFER CHARGE INTERVALENCE
4+ 4+ 2+ 3+
n oh ynt ad le apie Fe Sapphire, blue and Kyanite both In -
2+
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10…. page on continued Color Corundum) of variety (a
Blue Sapphire Sapphire Blue
Afghanistan
Darrah Pech, Kunar Province, Province, Kunar Pech, Darrah
Beryl variety Aquamarine, Kala, Kala, Aquamarine, variety Beryl
blue. vibrant
2 4 8 ] is a a is ] ,OH) [S,Cl,SO (Na,Ca) Lazurite
Brazil Gerais,
Kyanite, Barra do Salinas, Minas Minas Salinas, do Barra Kyanite,
years.
to light has caused it to darken over the the over darken to it caused has light to
when Stan & Sue first bought it. Exposure Exposure it. bought first Sue & Stan when
translucent bluish green 25 years ago, ago, years 25 green bluish translucent
Vivianite, Bolivia This specimen was a a was specimen This Bolivia Vivianite,
Celestian Stan by Photos
this page have been colored as a result of IVCT. IVCT. of result a as colored been have page this
All the pictures on on pictures the All Transfer Charge Intervalance
FIGURE 9 Minerals Whose Color is the Result of of Result the is Color Whose Minerals 9 FIGURE
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11…. page on continued Color
Celestian
Kunzite Photo by Stan Stan by Photo
Celestian Stan by Photo
FIGURE 10 Green Green 10 FIGURE
blue. to topaz
blue color, or to change colorless colorless change to or color, blue
irradiated to either enhance the the enhance either to irradiated
commercial blue topaz has been been has topaz blue commercial
over 3 decades, nearly all all nearly decades, 3 over
For For Topaz Blue 14 FIGURE
spectrum. color the
orange range of of range orange - red the in light absorb mountain. mountain. Celestian Stan by Photos
tend to to tend ” holes “ These positions. seen in the topaz sand grain from a wash on the the on wash a from grain sand topaz the in seen
atomic lattice to to lattice atomic and the color fades to clear, as as clear, to fades color the and ”, heal “ Carbon atoms from their original original their from atoms Carbon
radiation. Exposure to the Sun causes the damaged damaged the causes Sun the to Exposure radiation. electron. The radiation has dislodged dislodged has radiation The electron.
topaz from Topaz Mt., UT has been exposed to natural natural to exposed been has UT Mt., Topaz from topaz centers that are not occupied by an an by occupied not are that centers
colored colored - sherry This
diamond (green) actually have color color have actually (green) diamond
Topaz 13 FIGURE
aua o laboratory or Natural irradiated irradiated -
pink tourmaline Figures 10 Figures tourmaline pink 14. -
topaz (most blue topaz on the market), market), the on topaz blue (most topaz
irradiated blue blue irradiated - laboratory topaz, brown
amethyst quartz, green Kunzite, some some Kunzite, green quartz, amethyst
Fluorite, smoky Quartz, some some Quartz, smoky Fluorite,
: purple Fluorite, blue blue Fluorite, purple : Examples
.
radiation color radiation - pre
Photo by Stan Celestian Stan by Photo
traps, and the color will fade or return to its its to return or fade will color the and traps,
induced darkening induced - ter . .
enough energy to free the electrons from their their from electrons the free to energy enough tals, and cause color cen- color cause and tals,
may radiation ultraviolet or Heat introduce introduce ture of these quartz crys- quartz these of ture
rupt the atomic struc- atomic the rupt
mineral.
duced the energy to dis- to energy the duced
wavelengths of light, changing the color of the the of color the changing light, of wavelengths
in alpine granites pro- granites alpine in
these electrons may absorb various various absorb may electrons these
Radioactive minerals with- minerals Radioactive
a space (trap) within the crystal lattice. And And lattice. crystal the within (trap) space a Irradiation by Smoky
electrons may wander a bit and then settle into into settle then and bit a wander may electrons FIGURE 12 Quartz Made Made Quartz 12 FIGURE
their normal positions. These unattached unattached These positions. normal their
lattice, and electrons may be dislodged from from dislodged be may electrons and lattice,
(usually gamma rays) may damage the crystal crystal the damage may rays) gamma (usually
Photos by Stan Celestian Stan by Photos
from Rosiclare, IL IL Rosiclare, from : Radiation Radiation : Centers - F or Centers Color
and the purple one is is one purple the and
quartz) rose
Mine, Socorro Co., NM, NM, Co., Socorro Mine,
lemon yellow quartz, pink quartz (not (not quartz pink quartz, yellow lemon , Beryl are from the Blanchard Blanchard the from are
amber Calcite, blue Calcite, golden golden Calcite, blue Calcite, amber : Unknown The two blue specimens specimens blue two The
and Color Centers Centers Color and
FIGURE 11 Fluorite Fluorite 11 FIGURE substitutions). atomic some with combination
molecular aggregates, and unknown (or in in (or unknown and aggregates, molecular
color centers, intervalence charge transfers, transfers, charge intervalence centers, color -
- vary results The color. the influence that minerals,
Natural or artificial radiation can effect changes to to changes effect can radiation artificial or Natural
RADIATION IONIZING
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11…. page on continued Color
diate/index.html
more more
Celestian Stan by Photo
ch.du/color_causes/Ra
remove green hues, and create a a create and hues, green remove fade. to seem not does -- http://minerals.gps.calte
blotch of inky coloration is stable stable is coloration inky of blotch Beryl (Aquamarine) is heated to to heated is (Aquamarine) Beryl
16. FIGURE 16 Blue Halite Halite Blue 16 FIGURE This This
ish. - pink blue color. Figure Figure color. blue
ish to to ish - orange from color the change these cause the the cause these
Beryl (Morganite) is heated to to heated is (Morganite) Beryl and and --- particles
.0000001 meter) meter) .0000001
intense. more become or
.000000001 to to .000000001
treated to cause the color to darken darken to color the cause to treated
- small very (very
Spodumene (Kunzite) is often often is (Kunzite) Spodumene
sized sized - colloidal into
17. aggregate and
Figures 26 and and 26 Figures atoms will migrate migrate will atoms
Prasiolite) Prasiolite) (Na). Those metal metal Those (Na).
Celestian Stan by Photo
variety called called variety
Amethyst. Heating by ), to produce metallic sodium sodium metallic produce to ), (Na ions sodium
+
FIGURE 17 Prasiolite Created Created Prasiolite 17 FIGURE turns it green (a (a green it turns color centers may migrate and join with with join and migrate may centers color
C, C, 500 about to color. Given time, the electrons trapped in in trapped electrons the time, Given color.
o
some amethyst amethyst some produced by radiation turn the salt to an amber amber an to salt the turn radiation by produced
Heating Heating . Fe In the case of blue Halite, color centers centers color Halite, blue of case the In
2+.
to to Fe converts permutation on Color Centers): Centers): Color on permutation : : Example
3+
interaction that that interaction Molecular Aggregate (this is a bit of a a of bit a is (this Aggregate Molecular
and IVCT IVCT and
may be related to to related be may
NHMLA 24210 NHMLA
treatment. This This treatment.
Angeles Angeles
created by heat heat by created
History Museum of Los Los of Museum History
(part amethyst and part citrine) is is citrine) part and amethyst (part
used courtesy of the Natural Natural the of courtesy used
brown). In fact, Ametrine Ametrine fact, In brown). - orange
Photo by Stan Celestian and and Celestian Stan by Photo
or turned to Citrine (yellow, orange, orange, (yellow, Citrine to turned or golden yellow color. color. yellow golden
Amethyst Quartz can be lightened, lightened, be can Quartz Amethyst , causing a a causing , Fe of creation
3+ 3+
radiation induces the IVCT IVCT the induces radiation
traps. their from electrons center
aka Heliodor Heliodor aka Natural Natural
accomplished by releasing color color releasing by accomplished
FIGURE 15 Golden Beryl Beryl Golden 15 FIGURE
turned clear. This probably is is probably This clear. turned
Smoky Quartz can be lightened or or lightened be can Quartz Smoky
15. Figure Beryl. blue is
, and the result result the and , Fe to Fe reduce will
follow: examples Some
2+ 3+
golden Beryl. Heating golden Beryl Beryl golden Heating Beryl. golden defects (such as those created by irradiation). irradiation). by created those as (such defects
to produce produce to Fe creates Irradiation atoms, and the subsequent subsequent the and atoms, of lattice lattice of ” healing “
3+ 3+
c) the rise in temperature facilitating the mobility of of mobility the facilitating temperature in rise the c)
fades. color
lattice; b) facilitating Intervalence Charge Transfers; Transfers; Charge Intervalence facilitating b) lattice;
reverse this process, and the purple purple the and process, this reverse
holes “ removing thus structure, in the atomic atomic the in ”
sunlight supplies enough energy to to energy enough supplies sunlight
arrangement of the atomic atomic the of arrangement - re to or traps, their
this case, ultraviolet (UV) light from from light (UV) ultraviolet case, this
related to a) releasing color center electrons from from electrons center color releasing a) to related
, to produce Amethyst Quartz. In In Quartz. Amethyst produce to , Fe
The physics that causes color change is generally generally is change color causes that physics The
3+
is created from from created is Fe when occurs This
4+ 4+
common, that it is the norm in the realm of faceted faceted of realm the in norm the is it that common, IVCT. an initiate to necessary energy
treatment (and irradiation, for that matter) are so so are matter) that for irradiation, (and treatment radiation (usually gamma rays) may supply the the supply may rays) gamma (usually radiation
contribute to color in some minerals. In fact, heat heat fact, In minerals. some in color to contribute (IVCT): (IVCT): Transfer Charge Intervalence
Heat, either natural or laboratory facilitated, can can facilitated, laboratory or natural either Heat,
continued: Radiation Ionizing
HEAT
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13... page on continued Color
and sphalerite. Figure 19, page 14. page 19, Figure sphalerite. and
realgar, orpiment, cinnabar, sulfur, cuprite, cuprite, sulfur, cinnabar, orpiment, realgar,
mineral will appear red to yellow, as in in as yellow, to red appear will mineral
22. - 21 Figures See color. of bands varying display
in the blue range of the color spectrum, the the spectrum, color the of range blue the in
displayed. This is also what causes an oil slick to to slick oil an causes what also is This displayed.
For example, if the frequency absorbed is is absorbed frequency the if example, For
causing a rainbow of colors to be be to colors of rainbow a causing thereby -- out
and cancel each other other each cancel and ” phase of out “ be may they higher state. Figure 18, page 14. page 18, Figure state. higher
with each other and reinforce the wavelength, or or wavelength, the reinforce and other each with absorbed) to effect the jump of electrons to the the to electrons of jump the effect to absorbed)
” ” phase in “ be may they other, each with interact the amount of energy necessary (light frequencies frequencies (light necessary energy of amount the
the layers. As the various reflected light rays rays light reflected various the As layers. the and that gap determines determines gap that and ”, gap band “ the is bands
different speeds, depending on the thicknesses of of thicknesses the on depending speeds, different freely. The energy difference between these two two these between difference energy The freely.
mineral and the tarnish, it is reflected back at at back reflected is it tarnish, the and mineral where they are quite mobile and able to move fairly fairly move to able and mobile quite are they where
oxidation layers, and the surface between the the between surface the and layers, oxidation band, into a higher energy band (conductive band), band), (conductive band energy higher a into band,
but all very, very thin. As light reflects off the the off reflects light As thin. very very, all but electrons to jump from their normal (or valence) valence) (or normal their from jump to electrons
layers of oxidation, that are different thicknesses thicknesses different are that oxidation, of layers -- heat). Inputs of various levels of energy can cause cause can energy of levels various of Inputs heat).
and chalcopyrite is caused by light passing through through passing light by caused is chalcopyrite and rather than break when impacted, and conduct conduct and impacted, when break than rather
Iridescence in hematite, bornite, bornite, hematite, in Iridescence Interference (hence the ability to conduct electricity, deform deform electricity, conduct to ability the (hence
they can be very mobile mobile very be can they -- molecules or atoms OPTICS PHYSICAL
mineral, rather than being bound to individual individual to bound being than rather mineral,
whole the by shared are bands) (or shells outer the
blue. produces conductors with impurities, the electrons in in electrons the impurities, with conductors - semi
produces a yellow color, while boron boron while color, yellow a produces galena and pyrite, oxides, sulfosalts), and and sulfosalts), oxides, pyrite, and galena
conductors), a Nitrogen impurity impurity Nitrogen a conductors), - semi conductors (sulfides (sulfides conductors - semi (metals), such as as such --
And in diamonds (which are are (which diamonds in And Very simply put, in minerals that are conductors conductors are that minerals in put, simply Very
GAPS BAND
Michigan. from specimen ” breed - half “ a is This
hopping of freely moving electrons. electrons. moving freely of hopping -
nry band energy diamonds that have been heated. been have that diamonds
Copper and Silver owe their distinctive colors to the the to colors distinctive their owe Silver and Copper
on the market are low quality quality low are market the on
Silver Native & Copper Native 20 FIGURE
Black Diamonds are rare, so most most so rare, are Diamonds Black
Topaz.
produce blue or pink colors in in colors pink or blue produce
Coupled with irradiation, heat can can heat irradiation, with Coupled
heating.
enhanced by by enhanced - color are Tourmaline
Green and blue varieties of of varieties blue and Green
blue. - violet
brings out the more desirable vivid vivid desirable more the out brings
brown. heat treatment treatment heat brown. - reddish
gray or or gray - purplish attractive - so - not
colors are created. Figure 20. Figure created. are colors
Zoisite (Tanzanite) is often a a often is (Tanzanite) Zoisite
emitted is less than that absorbed, other other absorbed, that than less is emitted - re
the color is silver; when the amount amount the when silver; is color the color. the of uniformity and intensity
emitted equals the amount absorbed, absorbed, amount the equals emitted - re commonly heated to improve the the improve to heated commonly
the metal. When the amount of energy energy of amount the When metal. the Corundum (Sapphire) is very very is (Sapphire) Corundum
emitted determines the color of of color the determines emitted - re is much
’. healed ‘ are
fall back to lower energy bands. How How bands. energy lower to back fall
deepens, and inclusions and cracks cracks and inclusions and deepens,
emit some of it, as they they as it, of some emit - re then but energy,
s (Ruby) red color color red (Ruby) s ’ Corundum
these band gap electrons absorb light light absorb electrons gap band these
silver, copper metallic lusters because because lusters metallic copper silver,
Heat continued: Heat
Metals have characteristic opaque gold, gold, opaque characteristic have Metals
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VOLUME 49, Issue 7 Issue 49, VOLUME
13... page on continued Color
dakotamatrix.com Minerals Matrix Dakota Loomis, Tom of permission with A photo Celestian, Stan by E - B Photos
Cuprite (var. chalcotrichite), Ray Mine, Pinal Co., AZ. AZ. Co., Pinal Mine, Ray chalcotrichite), (var. Cuprite - E China; Province, Guizhou Mine,
Sphalerite, Silver Bell Mine, Pima Co., AZ; D D AZ; Co., Pima Mine, Bell Silver Sphalerite, - C CA; NP, Lassen Hell, Bumpas in fumerole Cinnabar, Wanshan Wanshan Cinnabar, -
Realgar (red) and Orpiment (yellow), Getchell Mine, Humboldt Co., NV; B B NV; Co., Humboldt Mine, Getchell (yellow), Orpiment and (red) Realgar - A spectrum. Sulfur crystals at a a at crystals Sulfur -
end of the color color the of end
lengths in the blue blue the in lengths
bopin f wave- of absorption
yellow colors to to colors yellow
all owe their red to to red their owe all
These five minerals minerals five These
Gaps Band
Minerals Colored by by Colored Minerals
FIGURE 19 19 FIGURE
D
B
E
C
A
s color will be depleted in the wavelengths absorbed. absorbed. wavelengths the in depleted be will color s ’ mineral
Diagram by Susan Celestian Celestian Susan by Diagram
into the conduction band. The energy necessary for that jump is called the Band Gap. And a a And Gap. Band the called is jump that for necessary energy The band. conduction the into
the absorption of light energy, electrons, in outer shells of atoms in the Valence Band, may jump jump may Band, Valence the in atoms of shells outer in electrons, energy, light of absorption the
band of electrons that are not tied to any specific atoms. This is the Conduction Band. With With Band. Conduction the is This atoms. specific any to tied not are that electrons of band
conducting metals (and metals), there is a partially a is there metals), (and metals conducting - semi In Gap Band 18 FIGURE occupied occupied -
BAND VALENCE
BAND GAP BAND
SOURCE
LIGHT
BAND CONDUCTION
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VOLUME 49, Issue 7 Issue 49, VOLUME
Color continued on page page on continued Color 14…. 24. - 23 Figures orange. and red
350 nanometers) produce produce nanometers) 350 - (150 spheres
Photo by Stan Celestian Stan by Photo produce blue and violet; while larger larger while violet; and blue produce
stack of spheres. of stack
spheres (< 150 nanometers) typically typically nanometers) 150 (< spheres
a different angle of the the of angle different a
of the spaces between them. Small Small them. between spaces the of
is rotated,and exposes exposes rotated,and is
determined by the size of the spheres, and and spheres, the of size the by determined
Aurora, as a specimen specimen a as Aurora,
See Figure 20. The color of the the of color The 20. Figure See is is ” fire “
change like the the like change
flashes before our eyes. eyes. our before flashes ” fire “ characteristic The colors colors The ”. fire “
interfere with each other, and the the and other, each with interfere light waves creates creates waves light
diffracted as it passes through, light waves waves light through, passes it as diffracted light. Interference of of Interference light.
causes diffraction of of diffraction causes size and regularly arranged, light is is light arranged, regularly and size
gauntlet of spheres, spheres, of gauntlet
silica. When these spheres are uniform in in uniform are spheres these When silica.
s s ’ Opal Australia
: Opal is composed of tiny spheres of of spheres tiny of composed is Opal : Opal
Opal From From Opal
FIGURE 24 Fire Fire 24 FIGURE
interference. interference.
this phenomenon is often also influenced by by influenced also often is phenomenon this
than it entered the opening. In the case of minerals, minerals, of case the In opening. the entered it than represent the color red). red). color the represent Celestian Susan by Diagram
emerges from the opening at a different angle, angle, different a at opening the from emerges The red lines represent areas of interference (they do NOT NOT do (they interference of areas represent lines red The
wave bends around the obstacle, or bends and and bends or obstacle, the around bends wave
change. colors the angles,
light encounters an obstacle or opening. The light light The opening. or obstacle an encounters light observes light interacting with the spheres from different different from spheres the with interacting light observes
Diffraction occurs when when occurs Diffraction Interference & Diffraction As one rotates an opal specimen in the light, and one one and light, the in specimen opal an rotates one As
characteristic of Fire Opal. Opal. Fire of characteristic ” fire “ the in resulting occurs,
each other, both constructive and destructive interference interference destructive and constructive both other, each
of Los Angeles Angeles Los of
NHMLA 40827 NHMLA
different directions. As the exiting light waves overlap overlap waves light exiting the As directions. different
the Natural History Museum Museum History Natural the
the spheres making up opal, it exits the opal headed in in headed opal the exits it opal, up making spheres the
Turgite used by courtesy of of courtesy by used Turgite
acts as a diffraction grating. As white light bends around around bends light white As grating. diffraction a as acts Photos by Stan Celestian and and Celestian Stan by Photos
s stack of spheres spheres of stack s ’ Opal Opal in Diffraction 23 FIGURE
(lower photo). (lower
the tarnish on chalcopyrite chalcopyrite on tarnish the
same process occurs with with occurs process same
rainbow of colors. The The colors. of rainbow
destructively, creating a a creating destructively,
interfere constructively constructively interfere --
at different rates, and bent, and as the rays emerge, they they emerge, rays the as and bent, and rates, different at
SOURCE travels through layers of varying thicknesses, it is slowed slowed is it thicknesses, varying of layers through travels
is colorful, because as light light as because colorful, is LIGHT
on Hematite (upper photo) photo) (upper Hematite on
of Goethite and Hematite) Hematite) and Goethite of
Turgite (maybe a combo combo a (maybe Turgite
thin, but irregular, film of of film irregular, but thin,
A A Tarnishes & Films of
FIGURE 22 Iridescence Iridescence 22 FIGURE
interference. by cancelled be will wavelengths
out of phase of out “ are waves that amount The energy. the out cancelling interference, destructive effect determines what what determines ”
the two light waves are are waves light two the ” B “ In question. in wavelength the reinforcing interference, constructive and and ” phase of out “
with each other and effect effect and other each with ” phase in “ are waves light two above, ” A “ In Waves Light of Interference 21 FIGURE
A B
Physical Optics continued: Optics Physical
12 page from continued Color ….
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VOLUME 49, Issue 7 Issue 49, VOLUME
15…. page on continued Color 26). Figure (See air the enter - re
waves refract again as they leave the prism and and prism the leave they as again refract waves
angles; and thus the colors separate out. The The out. separate colors the thus and angles;
component wavelengths, are refracted at different different at refracted are wavelengths, component
encounters the prism, refraction proceeds. The The proceeds. refraction prism, the encounters
speed. However, as each portion of the wave wave the of portion each as However, speed.
down. The rest of the wave proceeds at original original at proceeds wave the of rest The down.
Celestian Stan by Photos
the wave that first encounters the prism, slows slows prism, the encounters first that wave the
rainbow. the of colors the into up break and
a light wave encroaches upon a prism, the part of of part the prism, a upon encroaches wave light a as light rays penetrate faceted surfaces, refract, refract, surfaces, faceted penetrate rays light as
light wave bends, or is refracted. For example, as as example, For refracted. is or bends, wave light Citrine and Peridot sparkle with an array of colors colors of array an with sparkle Peridot and Citrine
approaches a different medium, at an angle, the the angle, an at medium, different a approaches This faceted faceted This Sparkle Gemstones 27 FIGURE
which rainbows are generated.) As light light As generated.) are rainbows which
wavelengths, i.e. colors. (This is the process by by process the is (This colors. i.e. wavelengths,
white light is split up into its component component its into up split is light white
iprin Dispersion Dispersion is the process whereby whereby process the is Dispersion
specimen at a different angle. angle. different a at specimen
Photo by Stan Celestian Stan by Photo
characteristic of the plagioclase feldspars. Inset: Inset: feldspars. plagioclase the of characteristic
striations, caused by polysynthetic twinning, twinning, polysynthetic by caused striations,
lamellae. In this image, you can see the parallel parallel the see can you image, this In lamellae.
colors, caused by diffraction off of internal internal of off diffraction by caused colors, - of - play
8 2 ] ) display a a display ) ] O (Ca,Na)[Al(Al,Si)Si Bytownite some
Some Labradorite (and (and Labradorite Some Labrodorite 25 FIGURE
27. Figure Diamonds.
separation). This is especially attractive in in attractive especially is This separation).
inside the stone, to enhance the color color the enhance to stone, the inside
light waves to be reflected back and forth forth and back reflected be to waves light
(Facets cause cause (Facets ’. fire ‘ or sparkle their stones
refraction and reflection of light, giving the the giving light, of reflection and refraction
The faceting of gemstones results in the the in results gemstones of faceting The
colors. colors.
Celestian Susan by Diagram
different angle, thereby splitting out into a rainbow of of rainbow a into out splitting thereby angle, different
Each component wavelength (color) refracts at a a at refracts (color) wavelength component Each
or less dense medium, the light wave bends or refracts. refracts. or bends wave light the medium, dense less or
25. Figure
As light waves slow upon entering a denser denser a entering upon slow waves light As Prism
, so desired by lapidarists. lapidarists. by desired so , labradorescence
FIGURE 26 Refraction and Dispersion of Light in a a in Light of Dispersion and Refraction 26 FIGURE
colors, or or colors, - of - play the causing
lamellae act as a diffraction grating, thus thus grating, diffraction a as act lamellae
plagioclase. Separations between the the between Separations plagioclase.
rich varieties of of varieties rich - sodium and rich - calcium of
formed by often parallel lamellae (thin layers) layers) (thin lamellae parallel often by formed
conditions are just right, the mineral is is mineral the right, just are conditions
series, within the feldspar group. When When group. feldspar the within series,
is an intermediate member of the plagioclase plagioclase the of member intermediate an is
8 4 : , , )O (Ca,Na)(Al,Si) Labradorite Labradorite
Physical Optics continued: Optics Physical
13 page from continued Color ….
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http://www.quartzpage.de/rose.html
https://www.gemselect.com/gem treatment.php - info/heat -
in.html - color
Celestian Susan by Photo
- change - that - https://www.geologyin.com/2016/02/gemstones
Eclipse. American Great the before us visited
omn rce (nbu smlx simplex) (Anabrus Cricket Mormon This creature creature This https://en.wikipedia.org/wiki/Pleochroism
http://minerals.gps.caltech.edu/files/visible/tourmaline/index.html
htm
http://minerals.gps.caltech.edu/COLOR_Causes/Metal_Ion/index.
https://www.gia.edu/doc/SP88A1.pdf
_Charge_Transfer_in_Jadeite_from_Burma
Jade_The_Optical_Spectrum_of_Fe3_and_Fe2_Fe3Intervalence
https://www.researchgate.net/publication/291776755_Lavender_
daniels.html - https://www.gamineral.org/writings/color
https://nature.berkeley.edu/classes/eps2/wisc/Lect7.html
http://www.minerals.net/resource/property/Color.aspx
http://www.minsocam.org/msa/collectors_corner/arc/color.htm
http://minerals.gps.caltech.edu/color_causes/
REFERENCES
its cloudy white to blue sheen. sheen. blue to white cloudy its
Photo by Stan Celestian Stan by Photo
plagioclase feldspar) feldspar) plagioclase
or Oligoclase, a a Oligoclase, or
Eocene). Eocene). - Paleocene Celestian Susan by Photo
orthoclase feldspar; feldspar; orthoclase
the Colton and Green River Formations (Upper (Upper Formations River Green and Colton the
Adularia, an an Adularia,
rock record are missing. Continuing up the slope are are slope the up Continuing missing. are record rock
Moonstone (either (either Moonstone
Formation. At that contact, about 100 million years of of years million 100 about contact, that At Formation.
waves gives gives waves
Paleocene Flagstaff Flagstaff Paleocene - mid the are rocks white horizontal
Scattering of light light of Scattering
Jurassic Twist Gulch Formation; and the the and Formation; Gulch Twist Jurassic - Mid
Moonstone Moonstone
The vertical red beds are the the are beds red vertical The UT Co., Sevier Salina,
FIGURE 28 28 FIGURE
Angular Unconformity in Salina Canyon, near near Canyon, Salina in Unconformity Angular
often white or bluish. Figure 28. Figure bluish. or white often
appearance called called appearance . It is is It . adularescence
effect is to produce a diffuse, glowing glowing diffuse, a produce to is effect
bent and scattered in many directions. The The directions. many in scattered and bent
interfaces between the different layers, it is is it layers, different the between interfaces
alternating layers. As light encounters the the encounters light As layers. alternating
These 2 minerals are intergrown as as intergrown are minerals 2 These
of a mixture of Albite and Orthoclase. Orthoclase. and Albite of mixture a of
feldspar, called Adularia, that is composed composed is that Adularia, called feldspar,
an intermediate variety of of variety intermediate an - Moonstone
display. will tint bluish a and scattered, selectively
appears white. Often the shorter wavelengths are are wavelengths shorter the Often white. appears
wavelengths are scattered equally, the mineral mineral the equally, scattered are wavelengths
the light wave encounters obstacles. If all all If obstacles. encounters wave light the
from a straight path. This deflection occurs when when occurs deflection This path. straight a from
SCENES of SUMMER 2017 SUMMER of SCENES
Scattering is the deflection of light light of deflection the is Scattering Scattering
14 page from continued Color ….
2017 OCTOBER
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VOLUME 49, Issue 7 Issue 49, VOLUME
VOLUME 49, Issue 7 Meeting Minutes — May 12, GNEISS TIMES 17 OCTOBER 2017
UPCOMING AZ MINERAL SHOWS Officers and Chairperson November 3-5 - Black Canyon City, AZ High Desert Helpers Rock-a-Rama Gem and Mineral Show; High Desert Park, President: Craig Jones.……..….…....208-523-9355 19001 E Jacie Ln; Fri 9-4, Sat 9-5, Sun 9-4; Admission: free. Vice President: Mel Canter ...... ….. 502-641-3118 Secretary: Judy Zimmerlee.....…….. 517-652-1355 November 18-19 - Payson, AZ Payson Rimstones Rock Club, Treasurer: Debra Keiser..………….. 928-684-1013 Inc.; Payson H.S./Longhorn Gym, west of Longhorn Rd., east Program Director: Dale Keiser..…… 928-684-1013 of McLane; Sat 9-5, Sun 10-4; Admission: $2, children 12 and Publicity: currently open position under free. Membership: Roma Hagan ..……….. 602-469-7662 Editor: Susan Celestian …………….. 602-361-0739 November 25-26 - Wickenburg, AZ Wickenburg Gem and Field Trip: Craig J, Bob B, Mel C Mineral Club; Wrangler Event Center, 251 S. Tegner St.; Sat Show Chair: Beth Myerson……...... 480-540-2318 9-5, Sun 10-4; Admission: free. Scholarship Chair: Steve Hill..….… 928-533-3825 January 5-7 - Mesa, AZ Flagg Mineral Foundation -- Flagg Historian: Jeanine Brown...... ….…. 928-684-0489 Gem & Mineral Show; Mesa Community College; 1833 W Southern Av; Fri-Sun 9-5; Admission: free.
January 12-14 - Globe, AZ Gila County Gem & Mineral Meetings are held the 2nd Friday most months at Society; Gila County Fairgrounds; Hwy 60, 3 miles north of Coffinger Park banquet room. Potluck dessert at 6:30 pm. Globe; Fri-Sat 9-5, Sun 9-4; Admission: $3 indiv, $5 couple, Business meeting at 7:00 pm. Exceptions: February and students/children free. December meetings are held on the first Friday of the January 19-February 11- Tucson, AZ There will be many month. We do not meet in the summer — no meetings in June, July or August. separate shows throughout Tucson during this period. For a general schedule, go to: Membership Dues: $15.00 Adults per Person http://www.tucsongemshows.net/coming.html $ 5.00 Juniors and Students
February 8-11 - Tucson, AZ Tucson Gem and Mineral Society; Tucson Convention Center; 260 S Church Av; Meeting Dates for 2017
Thur-Sat 10-6, Sun 10-5; Admission: $13, children 14 and Wickenburg: Jan 13, Feb 3, Mar 10, Apr 14, May 12, under free. Sept 8, Oct 13, Nov 10, Dec 1
February 8-11 - Mesa, AZ Apache Jct Rock and Gem Club; Stanton meets Thursday after the Wickenburg meetings. Skyline High School, 845 S Crimson Rd.; Sat 9-5, Sun 10-4; Jan 19, Feb 9, Mar 16, Apr 20, May 18, Sept 14, Oct 19, Admission: $3 adults, $1 students, children 12 and under free. March 24-25 - Anthem, AZ Daisy Mountain Rock and Mineral Club; Boulder Creek High School Gym, 40404 N Gavilan Peak http://www.wickenburggms.org/ Pkwy; Sat 9-5, Sun 10-4; Admission: $3 adults, $2 seniors and children, children 12 and under free. If you ever have photos from a club field trip, send a
couple to Dale, for posting on the website. If you are travelling, a good source of shows AND clubs is http://www.the-vug.com/vug/vugshows.html or http://www.rockngem.com/ShowDatesFiles/ShowDatesDisplay All.php?ShowState=AZ For out-of-the-country shows: NOTES FROM THE EDITOR http://www.mindat.org/shows.php?current=1
Have a geological interest? Been somewhere UPCOMING WGMS FIELD TRIPS interesting? Have pictures from a club trip? Collected
some great material? Write a short story (pictures would WHEN: Monday, October 30, 2017 be great). I’d like topic suggestions also.
WHERE: Harquahala Ghost Mine & Mining District I WHAT: History, dioptase would love to have some pictures from field trips! Snap a MEET: Goodwill parking lot in Wickenburg at 8 am couple and send them to me. BRING: water, lunch, shade, chair, hammer Deadline for the newsletter is the 27th of the month. ANY CAR CAN MAKE THIS TRIP Mail or Email submissions to: If you all have some place that you would like to go, Susan Celestian, editor let Craig J. 208-681-4770 or Mel C. 502-641-3118 6415 N 183rd Av know. This is your club. Let’s go out and have Waddell, AZ 85355 some fun. [email protected] Susan Celestian, editor For Wickenburg Gem and Mineral Society, Inc 6415 N 183rd Av Waddell, AZ 85355