Keystoneite
Keystone Mine, Magnolia Mining District, Boulder County, Colorado, USA
Acicular crystals of keystoneite on quartz. Associated minerals, not in the photograph, include, magnolite, coloradoite, and native mercury. Part of the co-type specimen. Previously in the collection of William W. Pinch. Brent Thorne specimen and photograph.
© Brent Thorne 2010