Identification of Minerals

Although nearly 2500 minerals are know to occur within Earth's crust, most are rare, with only about 100 occurring in abundance. Of those 100 minerals, 15 make up the common rock-forming minerals and some of the remainder have some economic value.Determine whether your mineral is light-colored or dark-colored (nonmetallics only). Determine whether your sample has cleavage. Your choices have been narrowed down, using the chart (which you will be taken to) see which physical properties match up with your mineral.A mineral is a naturally occurring, inorganic, solid which possesses a characteristic internal atomic structure and a definite chemical composition.

If we take the definition of a mineral term by term, it becomes easier to understand.

Minerals must occur naturally. This means man-made substances such as steel would not be considered to be minerals.

Inorganic substances are those substances that are not living and are not formed by living processes.

Crystalline solids are those solids in which the atoms composing the solid have an orderly, repeated pattern.

Minerals will have definite chemical compositions, but these compositions may vary within given limits.

Substances that have these features will also have distinctive physical properties such as color, crystal form, cleavage, luster, streak, etc. •"A mineral is an element or chemical compound that is normally crystalline and that has been formed as a result of geological processes" (Nickel, E. H., 1995).

•"Minerals are naturally-occurring inorganic substances with a definite and predictable chemical composition and physical properties." (O' Donoghue, 1990).

•"A mineral is a naturally occurring homogeneous solid, inorganically formed, with a definite chemical composition and an ordered atomic arrangement" (Mason, et al, 1968).

•"These... minerals ...can be distinguished from one another by individual characteristics that arise directly from the kinds of atoms they contain and the...