Mineralogy is an earth science that involves the chemistry, crystal structure, and physical (including optical) properties of minerals. Studies also include the processes of mineral creation and destruction.
The International Mineralogical Association (IMA) is an organization whose members are organizations representing mineralogists in individual countries. Its activities include managing naming of minerals.
As of late January of 2002 there are 3910 species of mineral recognized by the IMA. Of these, perhaps 150 can be called "common," another 50 are "occasional," and the rest are "rare" to "extremely rare."
See also: Georg Agricola, List of minerals