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).

This specemin is from Brazil. Lepidolite is the white material, The rest of the rock is a gneiss schist. A macro focus lens was used to blur the mirror like mica and reduce glare.
Lepidolite is monoclinic, crystals are prismatic, it is usually in granular masses resembling limestone. It has a hardness of 2 to 4 mhos, SG of 2.8 to 2.9, is red, rose, lilac, white, gray, greenish or brown. It occurs in pegmatite, granites and gneisses. The specemin in the photo was with gneiss. It is associated with tourmaline, cassiterite, muscovite, albite, and topaz. It is a important source of lithium.

From USGS: "Lithium is sold as brines, compounds, metal, or mineral concentrates depending on the end use. Lithium's electrochemical reactivity and other unique properties have resulted in many commercial lithium products. For many years, the majority of lithium compounds and minerals were used in the production of ceramics, glass, and primary aluminum. Growth in lithium battery use and decreased use of lithium in aluminum production has resulted in batteries gaining market share. In 2007, batteries became the leading end use for lithium for the first time. SQM listed the main markets for lithium as follows-batteries, 25%; ceramics and glass, 18%; lubricating greases, 12%; pharmaceuticals and polymers, 7%; air conditioning, 6%; primary aluminum production, 4%; continuous casting, 3%; chemical processing, 3%; and other uses, 22% (Sociedad Química y Minera de Chile S.A., 2008a, p. 37). The "other uses" category represents several smaller end uses including alloys, construction, dyestuffs, industrial bleaching and sanitation, pool chemicals, and specialty inorganics (FMC Corp., 2008a). These figures represent global markets; domestic end uses for lithium materials may not directly correspond to worldwide consumption, but the data necessary for making more reliable estimates were not available.