Minerals (Lab)

Five criteria used to determine if something is a mineral

1. Naturally occurring 2. Inorganic 3. Solid 4. Definite chemical composition 5. Ordered internal structure.

Fracture

The way a mineral breaks apart in an irregular or uneven manner.

Cleavage

The tendency of a mineral to break along flat surfaces or planes.

Hardness test

Hardness is tested by using the Mohs hardness scale. You can scratch the mineral with objects of known hardness (e.g., a fingernail, copper penny, glass, etc.) to determine its hardness.

Luster evaluation

Luster refers to how a mineral reflects light. It can be evaluated as metallic (shiny like metal) or non-metallic (glassy, pearly, dull, etc.).

Streak

The color of the powder a mineral leaves when scratched on a porcelain plate.