The document discusses several methods for mineral identification, including color, luster, streak, cleavage, fracture, hardness, specific gravity, acid testing, and special properties. Color can be affected by impurities and exposure to air. Luster describes how a mineral reflects light. Streak is the mineral's true color when rubbed on a plate. Cleavage and fracture describe characteristic breakage patterns. Hardness is measured on the Mohs scale. Specific gravity compares weight in air versus water. Acid testing can identify carbonate minerals through gas release. Some minerals fluoresce, taste salty, are radioactive, or show double refraction.

1. Chapter 2 Mineral Identification

2. Mineral Identification Tests color luster streak cleavage

3. Mineral Identification Tests fracture hardness specific gravity or heft acid test

4. Color minerals can be found in various levels of purity so they may not always look the same. ex: cinnabar, an ore of Mercury is red malachite, an ore of Copper is green What are the drawbacks of using color in identification?

5. Color Several minerals can have the same color Impurities can change the color of a mineral ex: iron causes quartz to turn from colorless to purple. titanium causes quartz to turn pink

6. Color Air causes minerals to change color. silver turns black and copper changes to green

7. Luster - how it shines metallic - shines like a metal must be a metal non - metallic - different kinds of shine because it is not metallic vitreous - glass adamantine - like a diamond pearly - soapy - waxy

8. Streak - true color done by marking mineral on porcelain plate mark left is true color of mineral some minerals will have a white streak , while other will have no streak

9. Cleavage - breakage planes minerals that tend to break apart easily along a flat surface mica - thin flat sheets graphite - flat surfaces in hexagons halite - cubes

10. Fracture minerals that break irregularly conchoidal - inside of a shell - obsidian fibrous - jagged edges - copper splintery

11. Scales of Hardness Mohs scale 1-10 1 - talc very soft 10 - diamond Field scale - 1-10 finger nail = 2 or less copper penny = 3 steel knife = 4 or 5 scratch glass = 6 to 7

12. Specific Gravity or Heft a comparison of a mineral that is weighted both in water and in the air this is a ratio it gives an idea of the number of atoms or molecules in a given space or size

13. Acid test Some minerals will fizzzzzzz when HCl is placed on it. calcite - limestone - marble will they are made of Ca CO 3 . the fizz is CO 2 gas being released

14. Special Properties Florescence - some minerals will glow when placed under ultra - violet light taste - halite tastes salty radioactivity - some minerals give off energy of their own double refraction - seeing double - calcite