This is the cluster of dark green actinolite crystals. Dimensions: 2.0 x 1.1 x 0.9″ (5.1 x 2.7 x 2.2cm). Weight – 1.3oz (38 grams). Origin: Russia, Siberia.
Some information about actinolite:
Actinolite is an amphibole silicate mineral. The name actinolite is derived from the Greek word aktis, meaning “beam” or “ray”, because of the mineral’s fibrous nature. Actinolite is commonly found in metamorphic rocks, such as contact aureoles surrounding cooled intrusive igneous rocks. It also occurs as a product of metamorphism of magnesium-rich limestones.
Some forms of actinolite are used as gemstones. One is nephrite, one of the two types of jade (the other being jadeite, a variety of pyroxene). Another gem variety is the chatoyant form known as cat’s-eye actinolite. This stone is translucent to opaque, and green to yellowish green color. This variety has had the misnomer jade cat’s-eye. Transparent actinolite is rare and is faceted for gem collectors.