1. Identifying Minerals
Geologists rely on several relatively simple tests to identify minerals
These tests are based upon a mineral’s physical and chemical properties

2. Identifying Minerals Color
Many times the color of a mineral is caused by the presence of trace elements or compounds.
One of the least reliable clues to a mineral’s identity
Example: Quartz can be found in a variety of colors, including red jasper, purple amethyst, and orange citrine.

3. Identifying Minerals Luster The way a mineral reflects light
Luster can be either metallic or nonmetallic
Silver, gold, copper, and galena have shiny surfaces that reflect light; they are said to have a metallic luster
Nonmetallic minerals such as calcite, gypsum, sulfur, and quartz to not shine like metals; they are described as being dull, pearly, waxy or silky

4. Identifying Minerals Texture
Texture describes how a mineral feels to the touch
The texture of a mineral might be described as smooth, rough, ragged, greasy, soapy, or glassy.
Texture is usually used in combination with other tests

5. Identifying Minerals Streak
Streak is the color of a mineral when it is broken up and powdered
A mineral’s streak does not always match its external color
The mineral is rubbed across an unglazed porcelain plate in order to produce a colored powdered streak on the surface of the plate

6. Identifying Minerals Hardness
Hardness is a measure of how easily a mineral can be scratched
The Mohs Hardness Scale rates minerals on whether they can scratch other minerals.
Example: Diamond is a 10 on the Mohs scale, since it cannot be scratched and can scratch all other minerals

7. Identifying Minerals Cleavage and Fracture
A mineral that splits relatively easily and evenly along one or more flat planes is said to have cleavage
Examples: mica breaks in sheets, halite breaks in three directions
Minerals that break with rough or jagged edges are said to have fracture
Examples: Flint, obsidian have an arclike fracture pattern resembling chain shells

8. Identifying Minerals Density and Specific Gravity
Density is the ratio of mass to volume of a substance
Density reflects the atomic weight and structure of a material
Specific gravity is the ratio of the weight of a substance to the weight of an equal volume of water at 4 degrees Celsius