2.6" Black Tourmaline (Schorl) and Orthoclase on Fluorite - Namibia

About Fluorite

Fluorite is a halide mineral comprised of calcium and fluorine, CaF2. The word fluorite is from the Latin fluo-, which means "to flow". In 1852 fluorite gave its name to the phenomenon known as fluorescence, or the property of fluorite to glow a different color depending upon the bandwidth of the ultraviolet light it is exposed to. Fluorite occurs commonly in cubic, octahedral, and dodecahedral crystals in many different colors. These colors range from colorless and completely transparent to yellow, green, blue, purple, pink, or black. Purples and greens tend to be the most common colors seen, and colorless, pink, and black are the rarest.

Schorl, also known as "black tourmaline" or "black schorl", is a black form of tourmaline that often occurs as lustrous prismatic crystals. The crystals can be stubby or elongated and typically feature lengthwise striations. Many schorl crystals have flattened pyramidal terminations. They can also form in radiating, columnar, and stalactitic aggregations, as well as small, needle-like inclusions within quartz (tourmalinated quartz) and in massive form.

Schorl is a basic sodium iron aluminum boro-silicate with the generic chemical formula NaFe2 + 3Al6(BO3)3Si6O18(OH)4 . It has been used for everything from jewelry to piezoelectric guitar pickups.