Black Spinel 4x8mm Faceted Rondelle - 15-16 Inch R1339 but can also appear silver

but can also appear silver

It can even exhibit various colors within the same specimen

Due to its color and clarity

but also for industrial purposes from watch gears and scientific instruments to sandpaper and other abrasives

Black Spinel 4x8mm Faceted Rondelle - 15-16 Inch R1339 but can also appear silverSpinel 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.