Minerals-inorganic, solid materials found in nature (can occur as gleaming crystals or as small grains in ordinary rocks)

Ways minerals form:

1. melted rock inside Earth called magma

2. melted rock that reaches the Earth's surface called lava

3. evaporation (ex-seawater evaporates, and other dissolved minerals, such as gypsum can crystallize)

4. precipitation-(extra material that can't be held by water separates and falls out as a solid)

Properties of minerals:

1. crystals-pattern of atoms

2. cleavage-minerals that split into pieces with smooth, regular planes that reflect light (peeling off a piece of sliced cheese)

3. fracture-break into pieces with jagged or rough edges (shaped more like hunks of cheese torn from an unsliced block)

4. color

5. streak-scraping a mineral sample across an unglazed, white tile, called a streak plate. (oddly enough the streak is not always the same color as the mineral)

6. luster-describes how light reflects from a mineral's surface

    a. metallic luster-shines like a metal

    b. nonmetallic luster- pearly, glassy, dull or earthy luster

7. hardness-Mohs scale-classifies hardness of a rock (talc soft, can be scratched with a fingernail, diamond hardest rock does not even leave a streak)

8. specific gravity-some minerals are heavier for their size than others (compares the weight of a mineral with the weight of an equal volume of water)

9. other properties:

    a. magnetic

    b. fizz in acid

    c. clear-see a double image through the mineral

    d. taste-salty

Common minerals:

Silicates

Carbonates

Gems: minerals that are rare and can be cut and polished (jewelry)

Ores: a mineral that contains enough useful substance that it can be sold for a profit

     a. iron-makes steel

     b. lead- for batteries

     c. magnesium-used in vitamins

     d. copper-wire and pans

Ores are processed after they are mined to extract the desired mineral.

Smelting plants melt ore and separate and remove most of the unwanted materials.

Sections 2&3

Igneous rocks-form when melted rock from inside the Earth cools and hardens.

     A. extrusive-when melted rock cools on the Earth's surface

          1. basaltic-dark colored igneous rocks

          2. lava cools so quickly that small crystals or no crystals are formed

             a. obsidian is formed when cooled quickly-black volcanic glass

             b. lava trapping large amounts of gas can contain many holes

          3. Extrusive rocks can form in two ways

              a. volcanoes erupt and shoot out lava and ash

              b. fissures, large cracks in the Earth, can open up and lava oozes out

     B. intrusive-when melted rock cools below the Earth's surface

          1. granitic-light colored igneous rocks

          2. magma cools below surface of the Earth.

               a. sits under surface and cools slowly

               b. slow cooling causes large crystals to form

Sedimentary Rocks-sediment can collect in layers to form rocks

     A. Rivers, ocean waves, mud slides and glaciers can carry sediment.

     B. Sediment is deposited by ice, wind, gravity or water.

     C. Three categories of Sedimentary Rocks:

          a. detrital Rocks-made of grains of minerals or other rocks that have

              moved and been deposited in layers

          b. chemical rocks-formed when seawater loaded with dissolved minerals

              evaporates

          c. organic rock-living matter dies, piles up and then is compressed into

              rock

              1. fossils-remains or trace of a once-living plant or animal

Metamorphic rocks-new rocks form when temperatures and pressure is high "change of form", rocks take on a whole new look.

     A. Foliated rocks-have visible layers or elongated grains of minerals

     B. Nonfoliated rocks-do not have distinct layers or bands (quartzite,

          marble, soapstone)

Rock cycle-Rocks are constantly changing from one form to another!!!!

a model or diagram to show how rocks are always changing.