Multi Spinel 4mm Table Cut Cube A Grade - 15-16 Inch 30X40 with darker shades being higher

with darker shades being higher in value

African Turquoise is not actually Turquoise

that were deposited in shallow sea beds

white and occasionally gray or brown

The inclusions can be so dense as to make the clear Quartz nearly opaque

Multi Spinel 4mm Table Cut Cube A Grade - 15-16 Inch 30X40 with darker shades being higherSpinel is a hard vitreous magnesium aluminum oxide, and comes in a range of other colors, but those varieties are transparent. Black Spinel not only has the dark color, but it is opaque as well, rendering its black especially deep and mysterious. Sometimes called the "Black Prince's Ruby" for its role in the English crown. It has been mistaken for ruby and sapphire at times, but can be distinguished by its structure and its lower relative hardness.