DOCSLIB.ORG

Mineralogical Notes on Mesolite and Scolecite from Japan

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Mineralogical Notes on Mesolite and Scolecite from Japan MINERALOGICAL JOURNAL, VOL . 5, No. 5, PP. 309-320, SEPT., 1968 MINERALOGICAL NOTES ON MESOLITE AND SCOLECITE FROM JAPAN KAZuo HARADA Section of Geology, Chichibu Museum of Natural History , Nagatoro 1417, Chichibu-gun, Saitama MAMORU HARA Geological and Mineralogical Institute, Faculty of Science, Tokyo University of Education, Otsuka, Tokyo and KAZUSO NAKAO Chemical Institute, Faculty of Science, Tokyo University of Education, Otsuka, Tokyo ABSTRACT Occurrence of mesolites and scolecite was confirmed in veinlets or amyg dales in andesitic or basaltic rocks in Japan. The results of chemical, physical and X-ray studies of these minerals are described, with their mineral associ ations and modes of occurrences. Introduction Mesolite and scolecite are usually classified as common fibrous zeolites, but there has been no report on the occurrence of these zeolites in Japan though the thermal and chemical data of mesolite from Tezuka, Nagano, Japan, was given by Koizumi (1953). However, our routine examinations of fibrous zeolites in the National Science Museum, Tokyo, recently confirmed that mesolite and scolecite are not so rare in Japan as hitherto believed. This paper deals with the 310 Mineralogical Notes on Mesolite and Scolecite from Japan descriptions of scolecite and mesolites from Japan. a) Mesolite from Tezuka, Nishisioda-mura, Chiisagata-gun, Naga no, Japan (coll. by Takaharu Imayoshi). This mineral occurs as fibrous aggregates, sometimes associated with heulandite, in the vein lets (2-3cm wide) in andesitic tuff breccia. The DTA, TGA and chemical analysis of this specimen were provided by Koizumi (1953). b) Mesolite from Oshima, Otsuki City, Yamanashi, Japan (coll. by the writers). This mineral occurs as fibrous aggregates closely associated with stilbite in amygdales (1-2cm) of thoroughly altered olivine basalt. c) Mesolite from Waniguchi, Itoigawa City, Niigata, Japan (coll. by Takaharu Imayoshi). This mineral occurs as silky fibrous spher ules (2-3cm) in the geodes of basalt soil. Some specimens show a hair-like crystal form. d) Scolecite from Hudakake, Kiyokawa-mura, Aiko-gun, Kana gawa, Japan (coll. by Yasue Oki). This mineral occurs as veinlets (1cm wide) in andesitic tuff breccia. Zeolite assemblages Under the polarizing microscope, some mesolites are found to contain scolecite. The Tezuka material contains about 5%, in volume of scolecite fiber. A zonal texture is apparent in the amygdales of the Oshima material; almost pure mesolite in the core of an amygdale is surrounded by the assemblage of mesolite and scolecite, and the latter is encircled by stilbite (Fig. 1). Scolecite from Hudakake often shows inter penetration-twins on {110} in the section perpendicular to the c-axis (Fig. 2). The Waniguchi and Hudakake specimens are almost pure, but detailed observations at high magnifications revealed a very small amount of thomsonite along the margins of the veinlets. Absence of quartz in all these specimens suggests that they have probably been crystallized at a low silica activity and under a non equilibrium condition. Physical data of those zeolites are shown in K. HARADA, M. HARA and K . NAKAO 311 Fig. 1. Microphotographs of mesolite, scolecite and stilbite from Oshima. A) Zoning of almost pure mesolite (M), scolecite+mesolite (SCM), and stilbite (ST), from core to rim, in an amygdale of olivine basalt (Parallel nicols). B) Aggregates of scolecite (SC) and mesolite (M) with Stilbite (ST). Stilbite (ST) is parallel to the wall of the amygdale (Parallel nicols). C) Aggregates of Scolecite (SC) and mesolite . (M) (Crossed nicols). Mesolite shows extremely low birefringence. Note: Scales represent 0.5mm in length. 312 Mineralogical Notes on Mesolite and Scolecite. from Japan Fig. 2. Microphotographs of scolecite from Hudakake. A) (001) section. Interpenetration-twins across (110) are recognized (Crossed nicols). B) Section parallel to the c-axis. Compact mass, Chalk like variety (1) and silky fiber (2) were chemically analysed (Crossed nicols). Note: Scales represent 0.5mm in length. Table 1. In some specimens 2V was not measured due to the very thin fibrous nature. Chemical data Pure specimens separated by hand-picking were analysed by the normal wet method. Mesolites from Oshima and Tezuka contained scolecite, in 5 or 10% in volume, as impurity owing to the difficulty in separation. Chemical data are shown in Table 1 together with Table 1. Chemical and physical data of mesolite, scolecite and stilbite. Notes: 1. Mesolite from Tezuka containing about 5%, in volume, of scolecite as impurity (Analyst, K. Nakao). 2. Mesolite from Oshima containing about 10%, in volume, of scolecite (a=1 .512, ƒÀ=1.517, ƒÁ =1.518, ƒÁ-ƒ¿=0.006andc•ÈX=19 .5•‹) as impurity (Analyst, M. Hara). 3. Silky fibrous (ƒ¿) and compact massive (b) scolecite (pure material) from Hudakake (Analysts, M. Hara (ƒ¿) and K. Nakao (b)). 4. Sodium-rich mesolite from Waniguchi (pure material) , Niigata Prefecture ((ƒ¿) fibrous aggregates; analyst, K. Nakao and (b) hair-like crystal; analyst , M. Hara). 5. Stilbite from Oshima (Analyst, M. Hara). K. HARADA, M. HARA and K. NAKAO 313 314 Mineralogical Notes on Mesolite and Scolecite from Japan other properties. In terms of structural formulae, these correspond to: Mesolite (Na1.567Ca2.294)3.861 (Fe+30.007Al5.856Si9.063)14.926O30•E8.548H2O (Tezuka, Nagano; with about 5% of scolecite as impurity), (Na1.999K0.003Ca2.318M g0.017)4.337 (Al6.355Fe+30.029Si8.735)15.119O30• 9.332H2O (Oshima, Yamanashi; with about 10% of scolecite as impurity), and (Na3.723Ca1.579)5.302 (A16.379Fe0.010Si8.488)14.877O30•E8.265H20 (Waniguchi, Niigata; pure material in fibrous aggregates). Scolecite (Na0.234K0.006Ca1.952Mg0.040)2.232(A14.172Fe+30.016Si5.982)10.170O20.6.120H2O (Hudakake, Kanagawa; pure material in silky fibers) and (Cal.581Na0.164K0.025)1.770 (A14.151Fe+30.017Si6.036)10.204O20•E6.196H2O (Hudakake, Kanagawa; pure material, chalk like variety in compact masses). Stilbite (Na0.823K0.043Ca3.991Mg0.091)4.948(Al11.823Fe+30.195Si24.715) 36.733O72•E25.387H2O (Oshima, Yamanashi; pure material). Chemical compositions of scolecite and mesolite are close to the data summarized and advocated by Foster (1965), but mesolite from Waniguchi contains much more Na2O and less CaO. From both X-ray and optical observations, this specimen is very pure, so that the chemical range of mesolite may extend toward the Na-rich side. The same specimen of mesolite from Tezuka analysed by Koizumi (1953) corresponds well to the writers' reexamination . Chemical composition of stilbite provides an important point. This stilbite contains much more Al2O3 and much less SiO2 than that hitherto reported and ad vocated (Cerny, 1965). This can be explained by the low silica activity prevailing during the crystallization . This stilbite is closely associated with mesolite and scolecite in the amygdales of olivine K. HARADA, M. HARA and K. NAKAO 315 basalt (Fig. 1). The multiplicity of mineralogical associations and variations seen within an amygdale or a veinlet was caused by subtle differences in the activity of cations during crystallization . Cation-exchange capacity Cation-exchange capacities were measured by Schollenberger and Shimon's method (Schollenberger & Shimon, 1945). The method was elucidated elsewhere (Harada & Tomita, 1967) and results are as follows: Mesolite from Tezuka, Nagano, and containing about 5% of scolecite as impurity gave 54.9meq/100g and the calculated c. e. c. based on chemical analysis gave 525.8meq/100g. The specimen from Oshima, Yamanashi, and containing about 10% of scolecite as impurity gave 119.5meq/100g and the calculated c. e. c. based on chemical analysis gave 499.6meq/100g. Scolecite from Hudakake, Kanagawa, which is a pure material in silky fibers, gave 104.5meq/100g and the calculated c. e. c. based on chemical analysis gave 531.0meq/100g. The maximum amounts of cation leached from the mesolite structure are 10.9% (Tezuka) and 23.9% (Oshima), and that from the scolecite structure is 19.7% (Hudakake), which are in contrast with the case of stilbite, where almost all the cation is exchangeable. (Harada & Tomita, 1967). The difference between these two cases maybe explained by the fact that these cations in scolecite and mesolite are bound to their frameworks stronger than those in stilbite, as surmised from the crystal structure of mesolite and scolecite (Pauling, 1930; Taylor, Meek & Jackson, 1933; Taylor, 1934). X-ray data X-ray powder data of mesolite from Tezuka and scolecite from Hudakake were indexed with the aid of their cell dimensions and 316 Mineralogical Notes on Mesolite and Scolecite from Japan Table 2. X-ray powder data of mesolite from Tezuka. K. HARADA, M. HARA and K. NAKAO 317 Table 3. X-ray powder data of scolecite from Hudakake. space groups so far reported: a=56.7A, b=6.54A, c=18.44A, ƒÀ=90•‹ and C3/2-C2 for mesolite (Hey, 1933), and a=18.48A, b=18.94A, c=6.54A, ƒÀ= 90•‹45•L and C4/8-Cc for scolecite (Wyart, 1933; Taylor, Meek & Jackson, 1933; Hey, 1936) as listed in Table 2 and 3 respectively. During the courses of the indexing, the cell dimensions were 318 Mineralogical Notes on Mesolite and Scolecite from Japan refined with the use of powder data with silicon as an internal standard. The results are: a=56.7A, b=6.53A, c=18.47A, ƒÀ=90•‹ (•}O.O1A for the cell edges) for mesolite, and a=18.48A, b=18.96A, c=6.54A, ƒÀ=90•‹45•L(•}0.02A) for scolecite. Mesolites from other localities showed no appreciable discrepancy. Heat treatments of mesolite The starting material was mesolite from Tezuka. The mesolite was pulverized to fine powder and spread on a silica glass slide. Heating experiments were performed at 100•Ž, 200•Ž, 300•Ž, 320•Ž and 340•Ž respectively for one hour. X-ray examination was then made at room temperature after each heat treatment (Fig.
Load more

Recommended publications
  • The Regional Distribution of Zeolites in the Basalts of the Faroe Islands and the Significance of Zeolites As Palaeo- Temperature Indicators
    The regional distribution of zeolites in the basalts of the Faroe Islands and the significance of zeolites as palaeo- temperature indicators Ole Jørgensen The first maps of the regional distribution of zeolites in the Palaeogene basalt plateau of the Faroe Islands are presented. The zeolite zones (thomsonite-chabazite, analcite, mesolite, stilbite-heulandite, laumontite) continue below sea level and reach a depth of 2200 m in the Lopra-1/1A well. Below this level, a high temperature zone occurs characterised by prehnite and pumpellyite. The stilbite-heulan- dite zone is the dominant mineral zone on the northern island, Vágar, the analcite and mesolite zones are the dominant ones on the southern islands of Sandoy and Suðuroy and the thomsonite-chabazite zone is dominant on the two northeastern islands of Viðoy and Borðoy. It is estimated that zeolitisa- tion of the basalts took place at temperatures between about 40°C and 230°C. Palaeogeothermal gradients are estimated to have been 66 ± 9°C/km in the lower basalt formation of the Lopra area of Suðuroy, the southernmost island, 63 ± 8°C/km in the middle basalt formation on the northernmost island of Vágar and 56 ± 7°C/km in the upper basalt formation on the central island of Sandoy. A linear extrapolation of the gradient from the Lopra area places the palaeosurface of the basalt plateau near to the top of the lower basalt formation. On Vágar, the palaeosurface was somewhere between 1700 m and 2020 m above the lower formation while the palaeosurface on Sandoy was between 1550 m and 1924 m above the base of the upper formation.
    [Show full text]
  • C:\Documents and Settings\Alan Smithee\My Documents\MOTM
    I`mt`qx1/00Lhmdq`knesgdLnmsg9Rbnkdbhsd This month’s mineral, scolecite, is an uncommon zeolite from India. Our write-up explains its origin as a secondary mineral in volcanic host rocks, the difficulty of collecting this fragile mineral, the unusual properties of the zeolite-group minerals, and why mineralogists recently revised the system of zeolite classification and nomenclature. OVERVIEW PHYSICAL PROPERTIES Chemistry: Ca(Al2Si3O10)A3H2O Hydrous Calcium Aluminum Silicate (Hydrous Calcium Aluminosilicate), usually containing some potassium and sodium. Class: Silicates Subclass: Tectosilicates Group: Zeolites Crystal System: Monoclinic Crystal Habits: Usually as radiating sprays or clusters of thin, acicular crystals or Hairlike fibers; crystals are often flattened with tetragonal cross sections, lengthwise striations, and slanted terminations; also massive and fibrous. Twinning common. Color: Usually colorless, white, gray; rarely brown, pink, or yellow. Luster: Vitreous to silky Transparency: Transparent to translucent Streak: White Cleavage: Perfect in one direction Fracture: Uneven, brittle Hardness: 5.0-5.5 Specific Gravity: 2.16-2.40 (average 2.25) Figure 1. Scolecite. Luminescence: Often fluoresces yellow or brown in ultraviolet light. Refractive Index: 1.507-1.521 Distinctive Features and Tests: Best field-identification marks are acicular crystal habit; vitreous-to-silky luster; very low density; and association with other zeolite-group minerals, especially the closely- related minerals natrolite [Na2(Al2Si3O10)A2H2O] and mesolite [Na2Ca2(Al6Si9O30)A8H2O]. Laboratory tests are often needed to distinguish scolecite from other zeolite minerals. Dana Classification Number: 77.1.5.5 NAME The name “scolecite,” pronounced SKO-leh-site, is derived from the German Skolezit, which comes from the Greek sklx, meaning “worm,” an allusion to the tendency of its acicular crystals to curl when heated and dehydrated.
    [Show full text]
  • Mineral Processing
    Mineral Processing Foundations of theory and practice of minerallurgy 1st English edition JAN DRZYMALA, C. Eng., Ph.D., D.Sc. Member of the Polish Mineral Processing Society Wroclaw University of Technology 2007 Translation: J. Drzymala, A. Swatek Reviewer: A. Luszczkiewicz Published as supplied by the author ©Copyright by Jan Drzymala, Wroclaw 2007 Computer typesetting: Danuta Szyszka Cover design: Danuta Szyszka Cover photo: Sebastian Bożek Oficyna Wydawnicza Politechniki Wrocławskiej Wybrzeze Wyspianskiego 27 50-370 Wroclaw Any part of this publication can be used in any form by any means provided that the usage is acknowledged by the citation: Drzymala, J., Mineral Processing, Foundations of theory and practice of minerallurgy, Oficyna Wydawnicza PWr., 2007, www.ig.pwr.wroc.pl/minproc ISBN 978-83-7493-362-9 Contents Introduction ....................................................................................................................9 Part I Introduction to mineral processing .....................................................................13 1. From the Big Bang to mineral processing................................................................14 1.1. The formation of matter ...................................................................................14 1.2. Elementary particles.........................................................................................16 1.3. Molecules .........................................................................................................18 1.4. Solids................................................................................................................19
    [Show full text]
  • Cavansite, a Calcium and Vanadium Silicate of Formula Ca(VO)(Si4o1o
    .. ,., Cavansite, a calcium and vanadium silicate of formula Ca(VO)(Si4O1o).4H.P, occurs as sky-blue to greenish-blue radiating prismatic rosettes up to~mm in size associated with its dimorph, pentagonite, in a roadcut near Lake Owyhee State Park in Malheur County, Oregon. Discovery of these two minerals is attributed to Mr. and Mrs. Leslie Perrigo of Fruitland, Idaho, (at this locality in 1961), and to Dr. John Cowles at the Goble locality in 1963 (see below). Associated with the cavansite and pentagonite are abundant colorless analcime, stilbite, chabazite, thomsonite and heulandite, as well as colorless to pale yellow calcite, and rare green or colorless apophyllite. This occurence and a similar emplacement (of cavansite only) near Goble, Columbia County, Oregon (co-type localities), represent the only known deposits of these two minerals in the United States. As determined by X-ray fluorescense and crystal stfiucture analysis, cavansite is orthorhombic, conforms to space group Pcmn (D2h 6), has a unit cell with a=lO.298(4), b=l3.999(7), c=9.6O1(2) Angstroms, contains four formula units, is optically biaxial positive and strongly pleochroic. Pentagonite, the dimorph, occurs as prismatic crystals twinned to form fivelings with a star­ shaped cross section. Also orthorhombic, it belongs to space group 12 Ccm21(C2v ), and has a unit cell with a=lO.298(4), b=13.999(7), and c=B.891(2) Angstroms, and also contains ··four formula units. The pentagonite crystals are optically very similar to cavansite, but are biaxially negative. The cell dimensions given tend to vary· to a small degree, presumably because of varying zeolitic water content.
    [Show full text]
  • Studies of the Zeolites Composition of Zeolites of the Natrolite Group and Compositional Relations Among Thomsonites Gonnardites, and Natrolites
    r-'1 ~ Q I ~ c lt') ~ r-'1 'JJ ~ Q.) < ~ ~ ......-~ ..,.;;j ~ <z 0 0 Q.) 1-4 rJ:J rJ:J N r-'1 ~ Q.) 0 ~ ..c ~ ~ ~ I r-'1 ~ > ~ 0 I ~ rJ:J 'JJ ..,.;;j Q.) < .....-~ 0 . 1-4 ~ C"-' 0 ~ ..,.;;j ~ 0 r-'1 00 C"-' Foster-STUDIES•. OF THE ZEOLITES-Geological Survey Professional Paper 504-D, E Studies of the Zeolites Composition of Zeolites of the Natrolite Group and Compositional Relations among Thomsonites Gonnardites, and Natrolites By MARGARET D. FOSTER SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY GEOLOGICAL SURVEY PROFESSIONAL PAPER 504-D, E UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON 1965 UNITED STATES DEPARTMENT OF THE INTERIOR STEWART L. UDALL, Secretory GEOLOGICAL SURVEY Thomas B. Nolan, Director The U.S. Geological Survey Library has cataloged this publication as follows: Foster, Margaret Dorothy, 1895- Studies of the zeolites. D. Composition of zeolites of the natrolite group. E. Compositional relations among thom­ sonites, gonnardites, and natrolites. Washington, U.S. Govt. Print. Off., 1965. v, 7; iii, 10 p. diagrs., tables. 30 em. (U.S. Geological Survey. Professional paper 504-D, E) Shorter contributions to general geology. Each part also has separate title page. Includes bibliographies. (Continued on next card) Foster, Margaret Dorothy, 1895- Studies of the zeolites. 1965. (Card 2) 1. Zeolites. I. Title. II. Title: Composition of zeolites of the natro­ lite group. III. Title: Compositional relations among thomsonites, gonnardites, and natrolites. (Series) For sale by the Superintendent of Documents, U.S. Government Printing Office Washington, D.C. 20402 - Price 25 cents (paper cover) Studies of the Zeolites Composition of Zeolites of the N atrolite Group By MARGARET D.
    [Show full text]
  • Action of Ammonium Chloride Upon Silicates
    Bulletin No. 207 Series E, Chemistry and Physics, 36 DEPARTMENT OF TEiE INTERIOR UNITED STATES GEOLOGICAL SURVEY CHARLES D. WALCOTT, DIRECTOR THE ACTION OF AMMONIUM CHLORIDE UPON SILICATES BY AND GKKOKG-IE Srj::ir, WASHINGTON GOVERNMEN.T PllINTING OFFICE 1902 CONTENTS. Page. Introductory statement......--..-..---.--.------.--.-..--.-.-----------. 7 Analcite-.....-.-.-.--.-.....-.--.'--------....--.-.--..._.-.---.-...---.--. 8 Leucite .....................'.................-....................^-..... 16 The constitution of analcite and leucite.........-..--.-..--...--.---------. 17 Pollucite---. ............................................................ 21 Natrolite--------------------------..-..-----------------.------ --------- 22 Scolecite ................,.:............-.....-.................--.--.... 24 Prehnite .....--.-............--.------------------------------ --------- 25 The trisilicic acids-.--.-.--..---..........-._-----...-.........-...----.- 26 Stilbite.............-..................-....-.-.-----...--.---.......... 29 Henlandite .......... .......................---.-..-.-..-...-----.--..--.. 81 Chabazite............................................................... 32 Thoinsonite...-.-.-..-...._.................---...-.-.-.----..-----..--.. 34 Lanmontite -.-.------.-..-------------.-..-.-..-.-------.-.-----........ 35 Pectolite ......:......... ......................................'.......;.., 36 Wollastonite ....'............................ ................:........... 39 Apophyllite. _.--._..._-....__.....:......___-------------....----..-...._
    [Show full text]
  • Infrared and Raman Spectroscopic Characterization of the Carbonate Bear- Ing Silicate Mineral Aerinite - Implications for the Molecular Structure
    This may be the author’s version of a work that was submitted/accepted for publication in the following source: Frost, Ray, Scholz, Ricardo, & Lopez Toro, Andres (2015) Infrared and Raman spectroscopic characterization of the carbonate bear- ing silicate mineral aerinite - Implications for the molecular structure. Journal of Molecular Structure, 1097, pp. 1-5. This file was downloaded from: https://eprints.qut.edu.au/84503/ c Consult author(s) regarding copyright matters This work is covered by copyright. Unless the document is being made available under a Creative Commons Licence, you must assume that re-use is limited to personal use and that permission from the copyright owner must be obtained for all other uses. If the docu- ment is available under a Creative Commons License (or other specified license) then refer to the Licence for details of permitted re-use. It is a condition of access that users recog- nise and abide by the legal requirements associated with these rights. If you believe that this work infringes copyright please provide details by email to [email protected] License: Creative Commons: Attribution-Noncommercial-No Derivative Works 2.5 Notice: Please note that this document may not be the Version of Record (i.e. published version) of the work. Author manuscript versions (as Sub- mitted for peer review or as Accepted for publication after peer review) can be identified by an absence of publisher branding and/or typeset appear- ance. If there is any doubt, please refer to the published source. https://doi.org/10.1016/j.molstruc.2015.05.008 Infrared and Raman spectroscopic characterization of the carbonate bearing silicate mineral aerinite – implications for the molecular structure Ray L.
    [Show full text]
  • Apophyllite-(Kf)
    December 2013 Mineral of the Month APOPHYLLITE-(KF) Apophyllite-(KF) is a complex mineral with the unusual tendency to “leaf apart” when heated. It is a favorite among collectors because of its extraordinary transparency, bright luster, well- developed crystal habits, and occurrence in composite specimens with various zeolite minerals. OVERVIEW PHYSICAL PROPERTIES Chemistry: KCa4Si8O20(F,OH)·8H20 Basic Hydrous Potassium Calcium Fluorosilicate (Basic Potassium Calcium Silicate Fluoride Hydrate), often containing some sodium and trace amounts of iron and nickel. Class: Silicates Subclass: Phyllosilicates (Sheet Silicates) Group: Apophyllite Crystal System: Tetragonal Crystal Habits: Usually well-formed, cube-like or tabular crystals with rectangular, longitudinally striated prisms, square cross sections, and steep, diamond-shaped, pyramidal termination faces; pseudo-cubic prisms usually have flat terminations with beveled, distinctly triangular corners; also granular, lamellar, and compact. Color: Usually colorless or white; sometimes pale shades of green; occasionally pale shades of yellow, red, blue, or violet. Luster: Vitreous to pearly on crystal faces, pearly on cleavage surfaces with occasional iridescence. Transparency: Transparent to translucent Streak: White Cleavage: Perfect in one direction Fracture: Uneven, brittle. Hardness: 4.5-5.0 Specific Gravity: 2.3-2.4 Luminescence: Often fluoresces pale yellow-green. Refractive Index: 1.535-1.537 Distinctive Features and Tests: Pseudo-cubic crystals with pearly luster on cleavage surfaces; longitudinal striations; and occurrence as a secondary mineral in association with various zeolite minerals. Laboratory analysis is necessary to differentiate apophyllite-(KF) from closely-related apophyllite-(KOH). Can be confused with such zeolite minerals as stilbite-Ca [hydrous calcium sodium potassium aluminum silicate, Ca0.5,K,Na)9(Al9Si27O72)·28H2O], which forms tabular, wheat-sheaf-like, monoclinic crystals.
    [Show full text]
  • Swiss Society of Mineralogy and Petrology
    Swiss Society of Mineralogy and Petrology http://ssmp.scnatweb.ch A MAJOR BREAKTHROUGH IN SWITZERLAND – THE GOTTHARD BASE TUNNEL On 15 October 2010, the last meter of rock separating the northern and southern parts of the eastern tube of the new Gotthard base tunnel disaggregated into dust. With a length of 57 km, it is currently the longest railroad tunnel in the world. It was built with a total deviation of only 1 cm vertically and 8 cm horizontally from the planned axis, and it traverses the Alps at an altitude of only 550 m above sea level. The tunnel was excavated using tunnel-boring machines and classical blasting in more schistose zones. Construction started in 1996, and to reduce the total construction time, excavation was carried out simul- taneously in several sections. The tunnel will be fully operational in 2017. Most rock types present at the surface are also found at tunnel level, almost 2.5 km below the surface, because the rock strata and foliations have a steep dip in this section of the Alps. The Gotthard region is famous for well-formed minerals occurring in Alpine-type fi ssures, and thus it was anticipated that mineralized cavities would be located in Quartz crystals 28 to 35 cm in length. PHOTO: PETER VOLLENWEIDER the new tunnel. For this reason, “mineral guards” were employed, whose duties were to collect, document and preserve mineralized clefts On May 13, 2011, the Natural History Museum in Bern opened a new encountered during tunnel excavation. The best sample material is permanent exhibit featuring one of the largest quartz crystal fi nds in currently exhibited in museums in Seedorf (Mineralienmuseum Schloss the Swiss Alps.
    [Show full text]
  • Mineral Collecting Sites in North Carolina by W
    .'.' .., Mineral Collecting Sites in North Carolina By W. F. Wilson and B. J. McKenzie RUTILE GUMMITE IN GARNET RUBY CORUNDUM GOLD TORBERNITE GARNET IN MICA ANATASE RUTILE AJTUNITE AND TORBERNITE THULITE AND PYRITE MONAZITE EMERALD CUPRITE SMOKY QUARTZ ZIRCON TORBERNITE ~/ UBRAR'l USE ONLV ,~O NOT REMOVE. fROM LIBRARY N. C. GEOLOGICAL SUHVEY Information Circular 24 Mineral Collecting Sites in North Carolina By W. F. Wilson and B. J. McKenzie Raleigh 1978 Second Printing 1980. Additional copies of this publication may be obtained from: North CarOlina Department of Natural Resources and Community Development Geological Survey Section P. O. Box 27687 ~ Raleigh. N. C. 27611 1823 --~- GEOLOGICAL SURVEY SECTION The Geological Survey Section shall, by law"...make such exami­ nation, survey, and mapping of the geology, mineralogy, and topo­ graphy of the state, including their industrial and economic utilization as it may consider necessary." In carrying out its duties under this law, the section promotes the wise conservation and use of mineral resources by industry, commerce, agriculture, and other governmental agencies for the general welfare of the citizens of North Carolina. The Section conducts a number of basic and applied research projects in environmental resource planning, mineral resource explora­ tion, mineral statistics, and systematic geologic mapping. Services constitute a major portion ofthe Sections's activities and include identi­ fying rock and mineral samples submitted by the citizens of the state and providing consulting services and specially prepared reports to other agencies that require geological information. The Geological Survey Section publishes results of research in a series of Bulletins, Economic Papers, Information Circulars, Educa­ tional Series, Geologic Maps, and Special Publications.
    [Show full text]
  • Cavansite Ca(V O)Si4o10 ² 4H2O C 2001 Mineral Data Publishing, Version 1.2 ° Crystal Data: Orthorhombic
    4+ Cavansite Ca(V O)Si4O10 ² 4H2O c 2001 Mineral Data Publishing, version 1.2 ° Crystal Data: Orthorhombic. Point Group: 2=m 2=m 2=m: As prismatic crystals, to 1 mm, elongated [001]; dominant forms 110 and 101 ; as spherulitic rosettes, to 5 mm. k f g f g Physical Properties: Cleavage: Good on 010 . Tenacity: Brittle. Hardness = 3{4 D(meas.) = 2.21{2.31 D(calc.) = 2.33 f g Optical Properties: Transparent. Color: Brilliant sky-blue to greenish blue. Luster: Vitreous. Optical Class: Biaxial (+). Pleochroism: Pronounced; X = Z = colorless; Y = blue. Orientation: X = b; Y = a; Z = c. Dispersion: r < v; extreme. ® = 1.542(2) ¯ = 1.544(2) ° = 1.551(2) 2V(meas.) = 52(2)± Cell Data: Space Group: P cmn: a = 9.792(2) b = 13.644(3) c = 9.629(2) Z = 4 X-ray Powder Pattern: Owyhee Dam, Oregon, USA. 7.964 (100), 6.854 (50), 6.132 (25), 3.930 (25), 3.420 (25), 2.779 (25), 4.531 (13) Chemistry: (1) (2) SiO2 49.4 53.24 VO2 17.1 18.38 CaO 11.5 12.42 H2O [21.0] 15.96 rem: 0.8 Total [99.8] 100.00 (1) Oregon; by XRF, H2O by estimation; actual H2O content established by structure analysis. (2) Ca(VO)Si4O10 ² 4H2O: Polymorphism & Series: Dimorphous with pentagonite. Occurrence: In a brown tu® partly ¯lling a fault ¯ssure (Lake Owyhee State Park, Oregon, USA); in a vesicular basalt and red tu® breccia, as cavity ¯llings and in calcite veinlets (Chapman quarry, Oregon, USA); in pores of altered basalt breccia and tu®aceous andesite (Poona district, India).
    [Show full text]
  • Thermal Stability of the Stilbite-Type Framework: Crystal Structure of the Dehydrated Sodium/Ammonium Exchange Form
    American Mineralogist, Volume 6E, pages 414419, 1983 Thermal stability of the stilbite-type framework: crystal structure of the dehydratedsodium/ammonium exchange form Wrlrnreo J. Monrren Katholieke Universiteit Le uven Centrum voor Oppervlaktescheikundeen Colloildale Scheikunde de Croylaan 42 8-3030Leuven (Heverlee),Belgium Abstract O-T bridges between them occurs. The cations are located at the six-ring site and the flat eight-ring site, and residual water moleculesat the boat-shapedeight-ring. The framework Oistortionsare cation-induced and readily affect the cuboid polyhedron of the framework which is formed by joining adjacent structural units' Introduction protons, but also cations such as K+ and Rb* with a sufficiently low ionic potential (Passaglia, 1980) may Stilbite-type minerals are zeolites with a two-dimen- "stabilize" the stilbite-type framework. The K and Rb sional interconnected channel system. Ten-membered forms do not undergo appreciable contraction and their ringsof (Si, Al) Oatetrahedra (free diametet4.1 x 6.24, destruction occurs only at fusion, i.e., at about 10fi)"C. Meier and Olson, 1978)Iimit the pore size of the largest As the dehydrated Ca-form exhibits a smaller fraction channels. These intersect with smaller ch-annelswith of broken T-O-T bonds (Alberti et al', 1978)than the eight-ring apertures(free diameter 2.7 x 5.7A, Meier and dehydratedNa-form (Alberti et al.,1978), the number of Olson, 1978). The inner surface should therefore be cations might be an important parameter. A further readily accessibleto small molecules and these minerals reduction of the number of cations is attempted here in could have a potential use as molecular sieves or cata- the study of a dehydrated Na-H-stilbite form.
    [Show full text]