Amphibole (formerly ''Uralite'')

Item Description

The Calumet Mine in Central Colorado is a well-known former iron-producer, but it's best known for its excellent Epidote specimens. Additionally, there are specimens of what used to be called "Uralite" for many years, from this mine, and they are notably distinctive in their appearance. It should be noted that "Uralite" was once thought to be a valid species, but it is now defined as being a variety of the Amphibole group. Calumet "Uralites" are most often pseudomorphs of an amphibole (Actinolite) after a pyroxene (Diopside / Augite). The crystals are typically not visible as they are found coated by Calcite, which is etched away with hydrochloric acid to expose the underlying "Uralite" crystals. This piece is a wonderful showy example featuring prismatic, soft green colored crystals measuring up to 1.6 cm, on very minor matrix. No major damage that I can see. A lovely example of these locally beloved classics. This piece is from the collection of Colorado mining legend, Dave Bergman. Dave is now retired from mining, but spent many years underground, including as the foreman and primary person in charge of recovering specimens at the famous Sweet Home Mine near Alma, Colorado during the late 1970s. He is also the maternal grandfather of Brian Kosnar. See Dave's photo mining at the Sweet Home on page 58 of Peter Bancroft's book "Gem and Crystal Treasures".