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 manganese carbonate mineral, Rhodochrosite, is a minor ore of manganese used mainly as a decorative stone and gemstone. Typically displaying shiny rose-red, intricately banded surfaces, it forms granular to compact cleavable masses, crusts, or columns. Hardness is 3.5 to 4, streak is white, and specific gravity is 3.7. Rhodochrosite occurs in moderate- to low-temperature hydrothermal ore veins, particularly of silver, lead, zinc, and copper, as well as in high-temperature metamorphic deposits.