Description: This is an extraordinary example of the species, an aesthetic cluster of thenardite crystals in bipyramidal, matte luster, translucent dark-gray crystals. They range to 4 cm on a side. The thenardite crystals are accompanied by snow white puffs of the rare borate, ulexite. For a large cabinet specimen, the crystals are remarkably pristine and for a gray specimen, it is remarkably aesthetic. These are generally considered best of species material, and good ones are seldom seen on the market today. From Al Ordway collection.