Uranophane is a hydrated uranium silicate. This rich and fine specimen features lustrous, canary-yellow crystals in a striking, flattened, acicular, radiating crystal aggregate with needles up to 2.3 cm long and as jackstraw nests of smaller crystals on matrix, which includes calcite. This is old, seldom available material from the Don Boydston Collection, a noted California collector. The accompanying Filer's label dates from 1949-1956, during the height of the uranium boom in the Southwest.