Black Spinel 4x6mm Faceted Rondelle - 15-16 Inch Spinel Crystal Quartz is a naturally

Crystal Quartz is a naturally occurring clear and colorless Quartz

Madre de Cacao is a very hard tropical wood with a visible grain

The combination of color and pattern variation are reminiscent of Red Creek Jasper

Mohs hardness 7

This prompted an alternative name for the gemstone: Princess Blue

Black Spinel 4x6mm Faceted Rondelle - 15-16 Inch Spinel Crystal Quartz is a naturallySpinel 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.