This is a pair of intergrown, barrel-shaped hanksite crystals, from Searles Lake, Trona, San Bernardino Co., California. The hanksite fluoresces a ghostly blue/white under both long and short wave UV light, but shows the brightest response under long wave UV. It is also phosphorescent. Hanksite is an interesting water-soluble mineral that contains both a sulfate and carbonate group, and forms in evaporite deposits in dry lake beds. This specimen measures 40 x 38 x 24 mm.
In the upper row, the hanksite crystals show fluorescence under long wave UV (left) and short wave UV (right). The lower pair of images show the same specimen from two different angles under visible light.