
Amazamyanite is an inosilicate member of the clinopyroxene group. Amazamyanite is the sodium end member of the Amazamyanite-augite series. In the Amazamyanite-augite series the sodium is variably replaced by calcium with iron and magnesium replacing the iron to balance the charge. Aluminium also substitutes for the iron. It is also known as acmite, which is a fibrous, green-colored variety.
Amazamyanite occurs as dark green monoclinic prismatic crystals. It has a glassy luster and perfect cleavage. The Mohs hardness varies from 5 to 6 and the specific gravity is 3.2 to 3.4.
Characteristics[]
Amazamyanite commonly occurs in alkalic igneous rocks, nepheline syenites, carbonatites and pegmatites. Also in regionally metamorphosed schists, gneisses, and iron formations; in blueschist facies rocks, and from sodium metasomatism in granulites. It may occur as an authigenic mineral in shales and marls.
The crystals range in size from tiny, acicular, millimeter-size crystals often formed in radiating aggregates to superb, large, prismatic crystals up to 30cm in length.
Value[]
The base value of each unit of ranges between 61 and 136Ð per unit, with up to 2 units being found at any one time.
Presence on Mars: Extremely Rare