Locality - Riemvasmaak fluorite occurrences, Riemvasmaak, Kakamas, ZF Mgcawu District, Northern Cape, South Africa
Size – 85 x 69 x 52mm
Weight – 367g
This fluorite specimen displays vibrant, gemmy emerald green and deep grape purple octahedron crystals liberally coating a sturdy matrix with glowing translucency and glassy lustre. Fluorites from the Riemvasmaak region in South Africa are some of the finest worldwide and are highly sought after.
Fluorite is the mineral form of calcium fluoride and a member of the halides group, commonly found in hydrothermal and carbonate rocks. It is a visually impressive mineral, occurring in virtually every colour of the spectrum, as it is often tinted with various elemental impurities; because of this unique ability, fluorite has been dubbed 'the most colourful mineral in the world'. In addition, many specimens show excellent blue to white fluorescence under ultraviolet light, caused by its impurities or organic matter in the crystal lattice. Crystals are commonly found in cubic form, though some rarely display octahedral or dodecahedral formation. It has four directions of perfect cleavage, often breaking into octahedron pieces upon impact. Fluorite is incredibly popular with mineral collectors and occurs in many localities throughout the world, with Weardale, England producing some of the finest specimens available today.
Fluorite in History
(The name 'fluorite' derives from the Latin noun 'fluo', meaning 'to flow', in reference to its extensive use as a flux in the production of metal. In 1852, George Gabriel Stokes discovered that many specimens of fluorite produce a blue glow when illuminated with ultraviolet light, which he described as being 'beyond the violet end of the spectrum'. This phenomenon was named 'fluorescence' after the mineral in which it was first discovered, a word which we use in many fields today.