Hardness

• a measure of how easily a mineral can be scratched.

• Any mineral with a greater hardness than another mineral will scratch that softer mineral

cleavage

• the ability of a mineral to split relatively easily and evenly along one or more flat planes.

Fracture

• is the ability of minerals to break with arc like, rough, or jagged edges.

Ore

• mineral that contains a useful substance that can be mined at a profit.

Gem

• valuable minerals that are prized for their rarity and beauty.