Rocks and minerals

Mineral

Naturally occurring, inorganic solid that has a crystal structure and a definite chemical composition.

What 5 things must a mineral have?

1. Must be formed by process that occur in the natural world

2. Must be inorganic, meaning that it cannot come from materials that were once part of a living thing

3. A solid-with definite shape and volume

4. Particles that make it line up in a repeating pattern which form a crystal

5. Has a definite chemical composition or range of compositions

Streak

Color of a mineral’s powder

Luster

How light is reflected from a mineral’s surface

Density

Each mineral has a characteristic density (D=M/V)

Hardness

Using the Mohs hardness scale, which ranks ten mineral from softest to hardest.

Crystal system

Crystals grow atom by atom to form a particular structure-these structures are grouped into six different categories based on the number and angle of crystal faces.

Clevage

If a mineral breaks easily along flat surfaces

Fracture

When a mineral breaks apart in an irregular way

Special properties

Magnetism and the ability to glow under an ultraviolet light

Crystallization

Process by which atoms are arranged to form a material with a crystal structure.

Geode

Rounded, hollow rock that is often lined with mineral crystal.

What are 2 ways a mineral can form?

1. crystallization of magma and lava

   • minerals form as hot magma cools inside the crust or as lava hardens on the surface. When these liquids cool to a solid state, they form crystals.

2. Crystallization of materials dissolved in water

   • when elements and compounds that are dissolved in water leave a solution (mixture in which one substance is dissolved in another). Crystallization occurs.

Veins

A narrow channel or slab mineral that is different from the surrounding rock.

Gemstone

Hard colorful mineral that has a brilliant or glassy luster, once cut and polished it is called a gem

Ore

A rock that contains a metal or other useful mineral that can be mined and sold at profit.

Granite

Light colored rock having high silica content

Basalt

Dark-colored rock that is low in silica

Texture

The look and feel of the rock’s surface, which is made up of particles of minerals or other fine rock called grains.

What are 3 different types of grain?

Grain size, shape and pattern

Igneous

Created when magma or lava cools and crystallizes

Sedimentary

Rock material that formed where rocks are broken down into smaller pieces or dissolved in water as rock erode or the remains of plants and animals are pressed and cemented together

Metamorphic

Forms when existing rock is changed by heat, pressure or chemical reactions

Rock cycle

A series of processed that change one type of rock into another type of rock

Extrusive rocks

Igneous rocks formed from lava that erupted onto earths surface

Intrusive rocks

Rock that formed when magma hardened beneath the earths surface

Texture

Geologist whether an igneous rock is extrusive or intrusive based on its texture

Composition

Can sometimes be determined by color of rock

Sediment

Small, solid pieces o material that come from rocks or remains of living things

Erosion

Form sediment by particles getting carried away from their source by wind and water

Deposition

Process by which sediment settless up of the water or wind carrying it

Compaction

Process that presses sediment together, growing thick layers that build up over millions of years

Cementation

Process in which dissolved minerals crystallize and glue particles sediment together

What can change any rock into a metamorphic rock?

Heat and Pressure beneath the earths surface

Foliated

Metamorphic rocks that have their grains arranged in parallel layers or bonds

Non-foliated

Mineral grain are arranged randomly