Chapter 3 ( aka Unit 7A): Minerals

Part I: Mineral Formation & Structure

1. What are minerals?

1. Minerals are natural, inorganic solids with a definite chemical composition and a particular crystalline structure .

Part I: Mineral Formation & Structure

2. What are the five characteristics of minerals?

2. Minerals are formed in nature and can’t be man made.Inorganic- not from living thingsSolidAlways the same chemicals in exact proportions.Crystals are always the same shape.

Part I: Mineral Formation & Structure

3. How manyminerals are found in the Earth’s curst?

3. Over 2,000

Part II: Mineral Composition4. What are Silicates?

QuartzSiO2

4. Made up of silicon, oxygen, and sometimes other elements. Silicates are the largest group of the minerals.

• Roman naturalist Pliny the Elder believed quartz to be water ice, permanently frozen after great lengths of time. (The word "crystal" comes from the Greek word for purity.) He supported this idea by saying that quartz is found near glaciers in the Alps, but not on volcanic mountains, and that large quartz crystals were fashioned into spheres to cool the hands. He also knew of the ability of quartz to split light into a spectrum. This idea persisted until at least the 1600s.

Cool Facts about Quartz

• Jewelry; watches • laboratory tubes and crucibles • radio, television, and radar• Quartz makes up almost all of two very

important building stones. Sandstone is a rock made up of quartz sand held together by a natural cement.

• Many more…. 

Uses of Quartz

Olivine - Mg2SiO4

• August birthstone• Igneous rock• Found in Meteorites

Part II: Mineral Composition5. What are Carbonates

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5. Carbonates are made up of CO3 and a metal•Calcite  is often the primary constituent of the shells of marine organisms; makes up sedimentary rock and limestone

CalciteCaCO3

HematiteFe2O3- herma , Greek word for blood;

Found on Mars; used as a “booby trap” in Egyptian tombs ( irritant to eyes and

skin)

Part II: Mineral Composition6. What are sulfides ?

6. Sulfides are made up of sulfur and one or more metals.

PyriteFeS2 or Fool’s Gold

Part II: Mineral Composition7. What are Sulfates ?

7. SO4 and one or more metals?Example:Gypsum :CaSO4 . 2H2O

Gypsum found plaster board linings for houses; fertilizer, surgical splints and casting

Part II: Mineral Composition8. What are Halides?

8. Consist of halogen, Cl, or F and a metal•Use for HID ( high intensity lamps)•Seen naturally in reefs

Part II: Mineral Composition9. Nativeelements –

9. Not combined with anything•Diamonds•Cooper•Nickel•Gold•Arsenic

Part III Mineral Identification

10. What are the properties of minerals?

10. Mineral properties include Luster, streak, cleavage, fracture, specific gravity, and hardness

Part III Mineral Identification

11. What is luster

11. Luster is the way a mineral reflects light; described as metallic, pearly, silky, glassy, dull, greasy

Part III Mineral Identification

12. What is streak?

12. Streak is the color of a mineral in powered form.

How? Rub a mineral across a streak plate

Part III Mineral Identification

13. What is color?

13. Color – different impurities can make the same minerals different colors

Part III Mineral Identification

14. What is cleavage?

14. Cleavage means the ability to break along smooth flat surfaces

Part III Mineral Identification

15. What is fracture?

15. Fracture means the way a mineral tends to break.

• Unevenly or evenly?