A green to black colored amphibolic mineral, CaNa(Mg,Fe)4(Al,Fe,Ti)3Si6O22(OH,F)2, created in the late phases of air conditioning in igneous stone.
A green to black amphibole mineral, of complex framework, created within the belated stages of air conditioning in igneous rock.
The common black colored, or dark-green or brown, variety of amphibole. (See amphibole.) It is one of the aluminous unit of this types, and is particularly described as its containing substantial iron. Additionally used as an over-all term to incorporate the entire species.
A common mineral, crystallizing in the monoclinic system with a prismatic angle of 124½°.
an eco-friendly to black colored mineral associated with the amphibole team; contains silicates of calcium and sodium and magnesium and iron