Purple Sugalite Disc Earrings with Sterling Silver. This Sugalite is mined from the Kalahari Desert. It was purchased through the Colbaugh Processing Plant in Kingman, AZ. Purple is an uncommon color in the mineral world, one of the most recognized species is sugalite. These small disc earrings are a rich, dark purple in color which pairs beautifully with the sterling silver accents. 1" Sugalite Donuts.