A mineral is a naturally occuring, homogeneous, solid with a crystalline atomic structure. Crystallinity implies that a mineral has a definite and limited range of composition, and that the composition is expressible as a chemical formula. Some definitions of minerals give them as inorganic materials, however both diamonds and graphite are considered minerals, and both are primarily comprised of carbon, which would make them organic. So this leads me, as an engineer, to believe that mineralogists do not have a good, precise definition of a mineral, but rather a loose definition. The definition above, is the most inclusive and would include all substances currently described as minerals. The key items that make something a mineral are occurring naturally, and the definite crystal structure, that is expressible as a chemical formula. Rocks that do not meet this criteria are referred to as amorphis - not having a definite structure or expressible as a chemical formula. Some elements that occur naturally and are minerals are arsenic, bismuth, platinum, gold, silver, copper, and sulphur.

THE DEFINITION OF ORGANIC: Organic chemistry is the study of those substances containing carbon in combination with hydrogen (H), and a few other non metals, namely oxygen (O), nitrogen (N), sulfur (S) and the halogens (F2, Cl2, Br2, and I2).

The Mineral, Bauxite, is a major source of Aluminum, and can contain as much as 35% Alumina (Al2O3). The major sources of US Bauxite are from Texas, Arkansas and Jamacia.

The two photos of bauxite ore have confused some readers, spurring them to inquire as to which types of bauxite ores they represent. So, in order to clear up the confusion, the red "mud" at the top, is the tailings of the bauxite process, what remains after the Al2O3 has been removed. The rock at the bottom is the bauxite ore as it came from the pit (ROM), prior to any processing. For further information on Bauxite Ore Processing, click on this text.