Black Spinel 5-6mm Drop Faceted Top Drill - 8 Inch R1111 Natural Turquoise may be cut

Natural Turquoise may be cut and polished

It is also one of the hardest

It is not a mineral

The presence of Manganese in the stone produces its color

Black Spinel 5-6mm Drop Faceted Top Drill - 8 Inch R1111 Natural Turquoise may be cutSpinel 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.