1. Mineral Characterisitics

2. Number 1Describe in Own Words ColorStreakLusterTexture Number 2 Number 3 Number 4 Number 5 Number 6 Number 7 Number 8

3. Color Most notable characteristic Caused by presence of trace elements Quartz= orange citrine (iron hydrates) purple amethyst (ferric iron), red jasper (iron oxide): Least reliable characteristic

4. Streak Color of the powder of a mineral Rub mineral across unglazed porcelain plate Sometimes, does not match color of mineral Pyrite (fool’s gold)= greenish- black Gold= yellow Only performed if softer than porcelain Can not be used to identify all minerals

5. Luster Way a mineral reflects light from its surface Metallic vs. Nonmetallic Dull, pearly, waxy, silky, greasy Caused by chemical compositions

6. Cleavage and Fracture How a mineral breaks Splits easily and evenly=cleavage Break with rough/jagged edges= fracture

7. Texture How mineral feels to the touch Smooth, rough, ragged, greasy, soapy, glassy

8. Hardness Most useful tool How easily it can be scratched Moh scale= 1-10 Determined by arrangement of mineral’s atoms

9. RatingType mineral What it can be scratched by… 1TalcBaby powder 2Gypsumfingernail 3Calcitebronze coin 4Fluoriteiron nail 5Apatiteglass 6Feldsparpenknife blade 7Quartzsteel knife 8Topazsandpaper 9Corundum 10Diamond

10. Density and Specific Gravity Density reflects atomic weight and structure. Useful, but sometimes differences are too small to be noticed by lifting Specific gravity: used by geologist. Ratio of weight to equal volume of water at 4 0 C

11. Special Properties Refraction: light bent in 2 directions when passed through mineral (zircon) Fizzing with contact of hydrochloric acid (calcite) Magnetic (iron ore) Distinctive rotten egg odor when streaked (sphalerite)

12. 1. Explain why color is not a good test for distinguishing between pyrite and gold 2. What test is most reliable for distinguishing between pyrite and gold. 3. What is a mineral’s texture? List several words used as a description 4. The mineral fluorite can be found in a variety of colors, yet its streak is always white. Why can fluorite be found in different colors? Why is the streak always the same?