Minerals are inorganic crystalline substances that are found naturally in the Earth. Mineralogy is the study of minerals, which are the building blocks of soil and vital to industry. Minerals are not mixtures but rather elements or compounds with a definite chemical structure. The most common elements in minerals are oxygen, silicon, and aluminum. There are different types of minerals including native elements, halides, sulfides, oxides, carbonates, and silicates. Minerals form crystals with geometric patterns that can be used to identify different minerals based on properties like color, streak, luster, hardness, cleavage, and acid testing. Valuable minerals can be mined for uses like metals, concrete, jewelry, and works of

1. 9 th Grade Chapter 9 Lesson 1 Pgs. 224-235 For student Use Only

2. Minerals Study of Minerals Minerals: inorganic (non-living) crystalline substances found naturally in the earth Building blocks of soil Vital to industry and society Mineralogy is the study of minerals Composition of Minerals: Are NOT mixtures, but are elements or compounds with definite chemical structure

3. Minerals Composition of Minerals: Most common element in minerals: Oxygen (47%) 2 nd most common element: Silicon (28%) 3 rd most common element: Aluminum (3%) Oceans contain minerals too Sodium Chloride Calcium Carbonate

4. Minerals Types of Minerals: Native Elements: substances that exist as a single naturally in the earth’s crust as a single, uncombined element Halides: Compounds containing the halogens Sulfides: minerals that contain sulfur (pyrite- fool’s gold is a sulfide)

5. Minerals Types of Minerals: Oxides: elements that contain oxygen Carbonates: elements that contain carbonate ion Silicates: largest group (92%) contain silicon Ex. Quartz Used for glass, computer chips, and silicone rubber Structures of Minerals: All minerals form crystals

6. Minerals Structure of Minerals: Crystal structure= geometric structures arranged by repeating three-dimensional patterns Crystals- flat surfaces (called faces and defined edges) Crystals of certain minerals have certain shapes This is used in mineral identification See page 227

7. Minerals Identifying Minerals: Surface color: some minerals have definitive color, some do not (can be changed by impurities) Streak Color: some minerals leave distinctive marks on unglazed porcelain (powder left as mineral scrapes over plate) Luster: the way light reflects off the surface of the mineral

8. Minerals Identifying Minerals: Hardness: the resistance to being scratched (use Mohs scale to determine level) Cleavage: where the mineral will break repeatedly Conchoidal Fracture- when broken looks like a smooth curved fracture Specefic gravity: Minerals have different densities as compared to water

9. Minerals Identifying Minerals: Acid Test: carbonates and sulfides react when HCl is dropped on their surface Special Properties: Magnetic- some minerals are magnetic Taste- some minerals have a taste (not the first method of ID) Fluoresce- glow when exposed to UV light Phosphorescent- glow after being exposed to UV light Radioactivity- some minerals are radioactive

10. Minerals Valuable Minerals: Minerals can be mined and used by humans. Used for: Metals Concrete Jewelry Works of Art

11. Minerals Valuable Minerals: Metals: Used for many substances Ore- any mineral that contains a valuable metallic element Other- copper, Iron, Aluminum, Nickel, Zinc, lead, tin, Uranium (fuel for reactors) Precious Metals- Gold, Silver, Platinum

12. Minerals Valuable Minerals: Precious Stones- (rare, valuable) Diamonds (hardest substance known to man), ruby, Corundum, sapphire, emerald, aquamarine Semi-Precious Stones- (not as rare or as valuable) Red Spinel, amethyst, zircon, tourmaline, opal, lapis lazuli, turquoise, chalcedony, jade