Grey Diamond 2-3mm Rough Nugget - 15-16 Inch R0387 It occurs with wave-like bands

It occurs with wave-like bands of charcoal gray

including lazurite

as well as some occurrences of dark gray

but truly unique

It displays a visual property called “pleochroism

Grey Diamond 2-3mm Rough Nugget - 15-16 Inch R0387 It occurs with wave-like bandsDiamond is a rare, naturally occurring mineral composed of pure carbon. Although most people think of diamonds as colorless, they actually occur in almost every color! Also, many people believe that diamonds are formed from coal, but it is not true. Diamonds actually form at high temperatures and pressures that occur in Earth's mantle about 100 miles below Earth's surface.