Locality: Calumet Mine, Turret District, Chaffee County, Colorado, USA
Size: 76 mm x 62 mm x 41 mm (3.0 in. x 2.4 in. x 1.6 in.)
Weight: 212 g (7.5 oz.)
Dark green actinolite to 5 mm pseudomorphed after diopside lining a pocket in the matrix. A pseudomorph forms when a mineral (actinolite, in this case) has replaced another (diopside), while retaining the form of the original mineral.