Rocks and Minerals

rock

A naturally occurring solid mixture of one or more minerals or organic matter

mineral

A solid inorganic substance of natural occurrence.

sedimentary

Formed from the compaction and cementation of loose particles

metamorphic

Rock recrystallized by heat and pressure

igneous

A type of rock that forms from the cooling of molten rock at or below the surface.

magma

A molten mixture of rock-forming substances, gases, and water from the mantle

lava

Magma that reaches Earth's surface

weathering

The breaking down of rocks and other materials on the Earth's surface.

erosion

Processes by which rock, sand, and soil are broken down and carried away

deposition

Process in which sediment is laid down in new locations.

streak

the color of a mineral's powder

luster

The way a mineral reflects light

hardness

A measure of how easily a mineral can be scratched

cleavage

the tendency of a mineral to break along planes of weak bonding

sediment

Minerals and small pieces of rock

fossils

Preserved remains of once-living organisms

gemstone

a hard, colorful mineral that has a brilliant or glassy luster

ore

a naturally occurring solid material from which a metal or valuable mineral can be profitably extracted.

Smelting

The process by which ore is melted to separate the useful metal from other elements.

geode

a hollow stone found on the earth that is lined on the inside with crystals

Crystallization

The process by which atoms are arranged to form a material with a crystal structure

Ways minerals can form

1. crystallization of magma and/or lava
2. crystallization of materials dissolved in water

vein

A narrow deposit of a mineral that is sharply different from the surrounding rock

Sedimentation

the process of settling or being deposited as a sediment.

Compaction and Cementation

the process by which sediments are pressed together under their own weight

density

amount of mass per unit volume

Mohs hardness scale

Ranks minerals on a scale 1-10; 1 being the softest, 10 being hardest