Properties of Minerals Take notes on page 31 and 32 of your science log (front and back) Write these notes exactly as they are shown!

What is a mineral? Inorganic (not formed by plants or animals) Solid Found in nature Orderly arrangement of atoms Quartz (silicon dioxide)

What’s the difference between a mineral and a rock? A rock is made of one or more minerals Granite is a rock, which has feldspar, quartz and mica. Feldspar is a mineral

How do minerals form? Lava or magma—as it cools, the atoms form orderly patterns. Evaporation—when seawater evaporates, crystals of minerals such as salt or gypsum form. Precipitation—extra materials that fall out of water solutions

Clues to Formation Size How crystals fit together

Properties Characteristics used to identify minerals

Crystals Solid materials with a repeating pattern of atoms Copper Sulfate crystals

Cleavage and Fracture Cleavage—splitting into thin sheets Fracture—breaking into rough edges Mica-one way cleavage Quartz-conchoidal fracture

Color Color can fool you! The best way to identify a mineral by color is a streak test —scraping an unknown mineral across a white, unglazed tile.

Luster How light reflects from a mineral’s surface. Is it shiny? Glassy? Dull? Metallic? Pearly?

Hardness Moh’s scale of hardness Classify minerals from 1 (softest) to 10 (hardest) Page 260 in the textbook

Specific Gravity Compares weight of mineral with weight of an equal volume of water.

Other properties Magnetism Double refraction Taste Reaction with Acid

Rock Forming Minerals Silicates – contain silicon and oxygen, example: feldspar Carbonates – contain carbon and oxygen, example: limestone

Gems Rare minerals that can be cut and polished. Diamonds are produced under pressure and brought to the surface by volcanic eruptions.

Ore Contains enough useful mineral to be sold at a profit. Must be processed to extract the mineral