Lab 2: Common Minerals I

Minerals

the basic component of all rocks. Defined as inorganic, naturally occurring solids with a definite crystalline structure and chemical composition.

Crystalline structure

refers to the repeating arrangement of atoms within the minerals crystal lattice

chemical composition

indicates which elements are present and in what ratio

Native elements

minerals composed of a single element

Ores

rocks containing high concentrations of native metals

Streak

the color of the mineral when powdered.

Porcelain streak plate

what do we use to show streak?

Luster

the appearance of a mineral in reflective light.

metallic, earthy, vitreous, resinous, pearly

what are the types of luster?

metallic

what luster looks like polished metal?

Diaphaneity

the ability of a mineral to transmit light. Transparent, translucent or opaque.

Cleavage

the tendency of minerals to break along definite places of weakness in the structure.

fracture

the tendency of a mineral to break along irregular surfaces