This Specimen has been sold.
6.9" Cactus Quartz (Amethyst) Crystal Cluster - South Africa
This is a beautiful, light purple, 6.9" wide cactus/spirit quartz (amethyst) crystal cluster from the Boekenhoutshoek area, Mpumalanga, South Africa. This is a larger cluster with really nice towers and even coloration. There is some areas where a black mineral appears on and within the quartz. This mineral may be goethite, but we can't definitively say. The slight orange coloration is attributed to iron oxidation.
Cactus quartz, often also referred to as spirit quartz, is a variety of quartz characterized by second-generation druzy crystals growing on the faces of larger quartz crystals. The small second-generation crystals point away from the prism and their orientation is not related to the crystallographic orientation of the central crystal. Cactus quartz is currently only known from the Magaliesberg Mountains region of South Africa, and comes in a variety of shades ranging from white to deep purple to orange colorations. The deep purple amethyst points are the rarest and most coveted by collectors.
Amethyst is a purple variety of quartz (SiO2) and owes its violet color to natural irradiation, iron impurities, and the presence of trace elements, which result in complex crystal lattice substitutions. It’s considered a semi-precious gemstone, and just two centuries ago was considered to have a value on par with diamonds, sapphires and rubies. The largest and best known amethyst deposits occur in southern Brazil and Uruguay but many localities around the world produce an amazing variety of amethyst crystals and formations.