Dims: 2.7" x 2.4" x 2.3" (6.9 x 6.1 x 5.8 cm)
Wt: 10.41 oz. (295.3 g)
Calumet Iron Mine, Salida, Chaffee Co., Colorado, U.S.A.
This Actinolite specimen, consisting of a variety that is called Uralite, has crystals that are larger than most that I have seen on similar pieces. The largest complete crystal measures 0.5 x 0.2 x 0.1" (1.3 x 0.5 x 0.3 cm), and several incomplete crystals have measurements larger than that. They occur in a monoclinic prismatic form that appears almost pseudotetragonal, but the basal terminatoins are slightly angled. All have a light greenish-gray coloration and a rather silky luster. Close examination of the crystals shows that they seem to be made up of very thin, compact, parallel fibers that have been aggregated into a prismatic form. This "aggregation" gives the material its silky sheen. Needless to say, it is opaque. Almost the entire specimen is composed of Actinolite, either crystalline or massive, but there does seem to be a tiny bit of white quartzite visible, and one small, clear quartz crystal does rest among some of the Actinolites.