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 element Silicon (Si) is not a mineral, since it does not occur in nature. Silicia's most common form is SiO2, or silica dioxide. Silica dioxide is a mineral. This is quartz or common sand's basic constituent. Silicon is produced by heating sand (SiO2) with carbon to temperatures around 2200C. At room temperatures, silicon exists in two forms, amorphous and crystalline. Amorphous appears as a brown powder while crystalline silicon has a metallic luster and a grayish color. The silicon in the photo is crystalline silicon.

Silicon is used in the manufacture of transistors, solar cells, rectifiers and microchips. Silicon dioxide (SiO2), silicon's most common compound, is the most abundant compound in the earth's crust, and comprises roughly 14% of the earth's crust. SiO2 is mined both as sand and as vein or lode deposits, for use in industry. Another example of an element that we could not live without, in the modern world.