"Actinolite is an intermediate member in a solid-solution series between magnesium-rich tremolite, Ca2Mg5Si8O22(OH)2, and iron-rich ferro-actinolite, Ca2Fe5Si8O22(OH)2. Mg and Fe ions can be freely exchanged in the crystal structure. 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."@en . "Actinolite are usually found as transparent, when cleaned, and are colored pale to dark green and black. When it is in the Asbestos form, it is white or grey. Actinolite is made when a mix of two rocks (tremolite and ferroactinolite amphiboles) come together."@en . "Actinolite are usually found as transparent, when cleaned, and are colored pale to dark green and black. When it is in the Asbestos form, it is white or grey. Actinolite is made when a mix of two rocks (tremolite and ferroactinolite amphiboles) come together."@en . . "Actinolite is an intermediate member in a solid-solution series between magnesium-rich tremolite, Ca2Mg5Si8O22(OH)2, and iron-rich ferro-actinolite, Ca2Fe5Si8O22(OH)2. Mg and Fe ions can be freely exchanged in the crystal structure. 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."@en . . "Actinolite"@en . .