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).

Native copper is both an element and a mineral. It's chemical formula is Cu, and it is almost pure, when found in this form. It has a crystalline cubic structure, is hexoctagonal. It has a hardness of 2.3 to 3 Mhos, a specific gravity of 8.5 to 9, a metallic luster and is very ductile. The streak of copper is red. It has a copper color, or is reddish. Copper will oxidize to black. The specimen in the photo came from Michigan.

Copper is one of the most important metals, is used widely in electrical equipment, wiring for homes and business, alloys, coatings and computer chips. Native copper is not a important source of copper, since it is relatively scarce. Massive low grade oxide and sulfide deposits are the primary source, with copper content ranging from 1% to 2%. The impurities in copper include gold and silver, and in fact some of the large copper mines are also some of the largest gold producers.