6" Sparkly AMETHYST Crystals +White CALCITE Sprays exU of AZ Valenciana for sale

This is an old-time Mexican amethyst cluster from Guanajuato. The amethyst is unique, as it is made up of tiny sparkly and sugary quartz crystals to .5mm, grouped together to form larger "crystals" to 12mm.  The amethyst color is a much-richer-than-usual lavender, and perched on top of each group is a single crystal that at 1 mm is slightly longer than the others, and surprise! it is colored a noticeably richer purple.  Dotted here and there are contrasting white calcite crystals arranged in delicate sprays to 10 mm.  This is literally a museum quality specimen, as it came to me from the University of Arizona collection, and comes with the University of Arizona Mineral Museum label.  Gift to the U. O AZ as part of the Hubert C. de Monmonier Collection.