Huebnerite

This specimen features delicate, feathery clusters of huebnerite crystals embedded in a snowy white quartz matrix. It is a rare and classic example of Colorado huebnerite, known for its sharp crystals with parallel growth and excellent colour. Among the purer end-member forms of the species, specimens of this material are difficult to obtain.

The specimen originates from the Adams Mine, just north of Gladstone, Colorado, on National Forest land. The mine, a tungsten occurrence, was owned by Thomas J. and Dorothy A. Mahon and began production in 1899. Mineralization consists of tungsten deposits hosted in Pliocene andesite, with an ore body striking N10E and dipping 85° SE. The local geology includes intra-ash flow andesitic lavas, and the workings comprise both surface and underground openings, including multiple adits. Production from the Adams Mine was reportedly substantial but remains unknown due to little known data.