Description
SPINEL CRYSTAL
This is the black spinel crystal with calcite and green diopside. Dimensions: 1.5 x 1.1 x 0.8″ (3.7 x 2.7 x 2cm). Weight – 0.9oz (25 grams). Origin: Russia, Yakutia.
Some information about spinel:
Spinel is the magnesium/aluminium member of the larger spinel group of minerals. Its name comes from the Latin word spinella, a diminutive form of spine, in reference to its pointed crystals.
Spinel crystallizes in the isometric system; common crystal forms are octahedra, usually twinned. Its hardness is 8, its specific gravity is 3.5–4.1, and it is transparent to opaque with a vitreous to dull luster. It may be colorless, but is usually various shades of red, lavender, blue, green, brown, black, or yellow.
This stone found as a metamorphic mineral in metamorphosed limestones and silica-poor mudstones. It also occurs as a primary mineral in rare mafic igneous rocks (More information about spinel).
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