GEOL 1101 LAB #1 ATOMIC STRUCTURE and MINERALS

NAME: GEOL 1101 LAB #1 ATOMIC STRUCTURE and MINERALS

1. What are the 3 basic atomic particles? Which are in the nucleus of an atom and which are in the orbits around the nucleus?

2. Describe the characteristics of all 3 atomic particles.

3. Define the following terms: ATOMIC NUMBER:

ATOMIC MASS (ATOMIC WEIGHT):

ISOTOPE:

4. A neutral atom has an atomic number of 25 and an atomic mass of 54. How many protons, neutrons, and electrons does this atom have? Look at the periodic chart (you can find one in your text, or on the internet at many sites, like http://www.ptable.com/) and name the element described above. number of protons = number of neutrons = number of electrons = name of element =

5. What are the two most common elements by weight in the crust and what is the percentage of each?

What is the general term used for these 2 elements combined together?

When these 2 elements are in minerals, they combine to make the basic molecule (“building block”) of over 95% of the minerals in the crust. What is the name, formula, and charge of this molecule? 6. Explain the difference between an amorphous solid and a crystalline solid.

7. List the seven most abundant positively charged ions by weight in the crust.

8. Define mineral. BE COMPLETE and list ALL parts of the definition!! 9. In the chart below, determine whether the item listed is a mineral or not a mineral. If the item is NOT a mineral, list WHY it does not fit the definition. SUBSTANCE MINERAL? Yes or no EXPLANATION gasoline brass sugar snow

REQUIRED MINERAL LIST (these are the minerals you should be able to identify on a test, when given a photo and all necessary characteristics):

METALLIC MINERALS: pyrite, galena, graphite (may also be nonmetallic); specular hematite, magnetite NONMETALLIC MINERALS: graphite (may also be metallic); hematite; limonite; biotite, pyroxene, amphibole, olivine, calcite, halite, muscovite, gypsum, sulfur, orthoclase (also called potassium feldspar or K-Spar); plagioclase; quartz

USE THE MINERAL IDENTIFICATION CHARTS BELOW TO HELP ANSWER QUESTIONS 10 – 15.

MINERAL IDENTIFICATION CHARTS REQUIRED METALLIC MINERALS METALIC MINERALS, HARDNESS > 5.5 (WILL SCRATCH GLASS)

PYRITE: brassy yellow color; black to greenish black streak; no cleavage; may show fracture; cubic crystals observed when sample has crystal form present

MAGNETITE: black color, may not look metallic; no cleavage, may show fracture; strongly magnetic

SPECULAR HEMATITE: metallic variety of hematite (iron oxide mineral); silvery “glitter” appearance; red to reddish brown streak

METALIC MINERALS, HARDNESS < 5.5 (DO NOT SCRATCH GLASS) GALENA: silver; perfect cubic cleavage; Hardness = 2 to 2.5; dark grey streak; Galena is the primary ore of lead (lead sulfide mineral) and has high specific gravity (feels very heavy)

GRAPHITE: native element mineral composed of carbon; dark grey to black color; may not look metallic; Hardness = 1; cleavage is usually not distinct due to graphite’s softness; easily writes on paper – graphite is used in pencils

REQUIRED NONMETALLIC MINERALS

NONMETALIC MINERALS, LIGHT COLOR HARDNESS < 5.5 (DO NOT SCRATCH GLASS)

CALCITE: calcium carbonate mineral (CaCO3); may be any color, commonly clear to white; usually translucent; perfect rhombehedral cleavage; Hardness = 3; strongly effervesces (fizzes) in acid

HALITE: sodium chloride mineral (NaCl); commonly clear to white color but often stained with impurities; perfect cubic cleavage; Hardness = 2.5; tastes salty

GYPSUM: commonly clear to white or light brown color; Hardness = 2 (easily scratched with fingernail); perfect cleavage in one direction and good cleavage in 2 other directions which makes gypsum tend to split into tabular, flat slabs

MUSCOVITE: type of the mica mineral group; perfect cleavage in one direction (sheet cleavage) and splits into very thin, flexible sheets; clear if thin sheets to light color; Hardness = 2.5

SULFUR: native element mineral; bright lemon yellow color; may be translucent or chalky looking; no cleavage but may show fracture REQUIRED NONMETALLIC MINERALS

NONMETALIC MINERALS, LIGHT COLOR HARDNESS > 5.5 (WILL SCRATCH GLASS)

ORTHOCLASE FELDSPAR (K-SPAR): the potassium rich variety of feldspar; commonly a pinkish- orange color (but may be other colors); Hardness = 6 to 6.5; 2 good directions of cleavage at 90°

PLAGIOCLASE FELDSPAR: the sodium –calcium rich variety of feldspar; the sodium rich varieties will be a light grey to white color; the calcium rich varieties are a darker grey; Hardness = 6 to 6.5; 2 good directions of cleavage at 90° ; shows striations on cleavage planes

QUARTZ: SiO2, may be any color (including dark browns), but is commonly translucent; white varieties are commonly a milky luster; no cleavage; excellent fracture shown on most samples; if crystal form is present, may see a pyramidal form; Harness = 7, easily scratches glass NONMETALIC MINERALS, DARK COLOR HARDNESS < 5.5 (DO NOT SCRATCH GLASS)

BIOTITE: type of the mica mineral group; perfect cleavage in one direction (sheet cleavage) and splits into very thin, flexible sheets; brown to black; Hardness = 2.5

GRAPHITE: native element mineral composed of carbon; dark grey to black color; may not look metallic; Hardness = 1; cleavage is usually not distinct due to graphite’s softness; easily writes on paper – graphite is used in pencils

HEMATITE: iron oxide mineral; no cleavage; variable hardness so may or may not scratch glass; commonly shows earthy luster; may have rounded forms; distinctive red to reddish brown streak

LIMONITE: iron oxide mineral; no cleavage; earthy luster; yellow –orange to brown color; yellow- orange to brown streak; may occur as a powdery covering on other rocks and minerals

NONMETALIC MINERALS, DARK COLOR HARDNESS > 5.5 (WILL SCRATCH GLASS)

PYROXENE: dark green to black color; good cleavage in 2 directions at 90° so that pyroxene tends to show a blocky to square shape; Hardness = close to 5.5 to 6, so samples do not always scratch glass

AMPHIBOLE: dark green to black color; good cleavage in 2 directions at 60’ and 120° so that amphibole tends to show an elongated shape; Hardness = close to 5.5 to 6, so samples do not always scratch glass

OLIVINE: green color, usually translucent; occurs as small rounded crystals; commonly seen as aggregates; no cleavage, shows good fracture; Hardness = 6.5 to 7 10. What is a carbonate mineral? Give an example from the list of minerals that you are required to identify.

11. What is the mineral shown below that is from the list of minerals that you are required to identify and is nonmetallic, light colored, soft enough to scratch with your fingernail (H = < 2.5), and has perfect sheet cleavage but also 2 other planes of cleavage so that it forms flat slabs?

12. Name a mineral from the list of minerals that you are required to identify that has the following properties. Some properties may be in more than one mineral, but you just need to list one. PHYSICAL PROPERTY MINERAL NAME striations effervescence in acid

Salty taste magnetic

Earthy luster

13. Define the following: CRYSTAL FORM (CRYSTAL FACE):

CLEAVAGE PLANE:

14. For each mineral shown below, detemine if the cleavage is: perfect in one direction (“sheet cleavage”); two planes at 90° (“stairstep”); cubic; rhombehdral; or if the mineral exhibits fracture. 14A. Mineral: Type of cleavage or fracture 14B. Mineral: Type of cleavage or fracture:

14C. Mineral: Type of cleavage or fracture:

14D. Mineral: Type of cleavage or fracture:

14E. Mineral: Type of cleavage or fracture: The following descriptions for each of the minerals above can help you identify the mineral:

14A: “fizzes” in acid; is softer than glass 14A NAME = ______

14B tastes “salty” 14B NAME = ______

14C: will scratch glass easily; translucent 14C NAME = ______

14D: thin sheets can be bent (flexible) 14D NAME =______

14E: will scratch glass but not as easily as 14C; distinctive pinkish color (listed on “Light Colored” Minerals chart above); NO striations

14E NAME = ______

15. Go to the website: http://facweb.bhc.edu/academics/science/harwoodr/geol101/labs/minerals/

The top of the web page has a mineral identification chart like the one in this lab. For this question, you will scroll to the bottom of this page and click on several minerals to identify. When you click on the number there is a photo and also additional photos in a link below. To determine the mineral’s hardness, you will click on a number in the “harness test” row and keep clicking till you determine the hardness. For example if a mineral was scratched at H = 3, but not scratched at H=2, the hardness is 2. After hardness, you will click on each of the other properties to determine what they are. This site also describes minerals without fracture as “irregular fracture” and others as “conchoidal fracture”

There is an identification worksheet below the properties test that you will use to select each property you determined. Then, using the charts in this lab and on the website, you determine the name of the mineral in the MINERAL NAME chart and click on “GRADE IDENTIFICATION”. BE SURE TO RESET ANSWER after each identification try.

For each of the samples below, I am giving you the crystal form for the mineral, since this is not a property we discuss in GEOL 1101. And some properties are not obvious so the answer is given.

MINERAL 4 (crystal form is hexagonal; be sure and click NAME #4:= additional images for more information)

MINERAL 6 (crystal form not present; color is gray): NAME#6 =

MINERAL 9 (crystal form not present): NAME #9 =

MINERAL 10 (crystal form is cubic; conchoidal fracture is not obvious): NAME #10 = MINERAL 11 (crystal form not present) : NAME #11 =

MINERAL 12 (crystal form not present, each tiny bright green mineral in the sample is actually what you identify which means this sample is actually a rock (aggregate of minerals)) : NAME #12 =

MINERAL 13 (crystal form is not present); NAME #13 =

MINERAL 16 (crystal form is cubic; conchoidal fracture is not obvious) ; NAME #16 =

MINERAL 17 (be sure and click on additional images; crystal form is rhombehedron);

NAME #17 =

MINERAL 19 (crystal form is not present; color is black) ; NAME #19 = ______

**** If you look at other samples, there is a mistake on the website for mineral 3, which is one of the required minerals for this class. It is listed as magnetic, which it is NOT!!)

16. Using the mineral identification charts in this lab, determine which photo below is pyroxene and which is amphibole. REMEMBER! The most distinctive property to help in distinguishing these two minerals is the cleavage!!!

MINERAL A = MINERAL B =