Systematic Collection

Over 3,000 different species of minerals are now recognized.   To bring order to this great number of minerals, mineralogists found it necessary to make a systematic classification of them.  Over the years, several different systems have been proposed.  The most generally recognized system classifies minerals on the basis of the negatively charged chemical group, or anion, present in atoms of the mineral.

According to this system, the major classes and subclasses recognized are: the native elements; the sulfides and their subdivision, the sulfosalts; the oxides and hydroxides and their subdivision, the columbite-tantalite series; the halides; the carbonates and their subdivision, the nitrates and borates; the sulfates; the phosphates; and the silicates.   Each of these classes is well represented in Hillman Hall.

This organization of minerals provides information about chemical composition and crystal structure of the minerals.  It is a changeable and expandable system.  Thus, as the structure of minerals becomes better known and new minerals are discovered, they can be accommodated by the system.