This is a gorgeous cluster of yellow cubic fluorite crystals from Meknes, Morocco. Many of the crystals have sharp, well defined edges and glassy smooth faces. Under long wave UV, these fluorite crystals fluoresce a vibrant purple color. Galena can also be found throughout what can be considered the matrix of these crystals.
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.
Galena is a lead based mineral that is in fact the primary ore of lead, and has been used for its lead content for thousands of years. Galena typically displays a gray metallic luster and forms cubes or octahedral crystals. The chemical composition of galena is PbS.