Black Spinel 3mm Natural Round - 15-16 Inch Color_Turquoise Rutile is the mineral name

Rutile is the mineral name for natural crystals of titanium dioxide

creating a unique "marbled" look

and Rutile as well

and is a result of trace amounts of copper or chromium

Black Spinel 3mm Natural Round - 15-16 Inch Color_Turquoise Rutile is the mineral nameSpinel 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.