Amphibole (formerly ''Uralite'')

Item Description

The Calumet Mine lies near Salida, Colorado and is a well-known former iron-producer, which is best known for its excellent Epidote specimens. Additionally, this mine has produced some distinctive specimens of what used to be called "Uralite" for many years. I will point out that "Uralite" was once a valid species, but it is now defined as being a variety of the Amphibole Group replacing a member of Clinopyroxene Group. Calumet "Uralites" are most often pseudomorphs described as Actinolite after Diopside / Augite. The crystals are typically not visible when the pieces come out of the ground, as they are 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 1.0 cm, on matrix. No major damage that I can see. A lovely example of these locally beloved classics.
Ex George Loud Collection No. 338 CO.3; 4834. George (born August 16, 1942) is a well-known mineral collector from Washington, DC and South Carolina respectively, and was a patent lawyer by trade for over 50 years. He assembled one of the great mineral collections in the U.S., comprising worldwide specimens, and in later years he sold the worldwide specimens to focus on minerals of the United States, specifically locality suites with an emphasis on amazing representation of species while still maintaining fine quality. The specimens remarkably range from micros to all the way up to large cabinets in size. We recently acquired most of his impressive 9000+ piece collection, and the VAST majority of these pieces will be offered here in the auctions, as we feel that everyone deserves and equal opportunity at acquiring these important, well-documented and fine quality specimens for their collections.
See: https://mineralogicalrecord.com/biographies_labels/george-loud for more information