Sapphire 4mm Faceted Round A Grade - 15-16 Inch 10mm It is often used in

It is often used in kiln furniture and foundry molds

everything from colorless to black

Formed deep underground during the cooling of magma

and opalescence or lustrous sheen in opaque samples

Biotite is a name used for a large group of black mica minerals that are commonly found in igneous and metamorphic rocks

Sapphire 4mm Faceted Round A Grade - 15-16 Inch 10mm It is often used inSapphires are precious gemstones, but unlike rubies, they come in a rainbow of colors besides red! They are all varieties of the mineral corundum, known for its incredible hardness, second only to diamond . This makes sapphires very durable and scratch resistant. Formed deep underground during the cooling of magma, sapphires get their various colors from trace elements. Iron gives them blue, the most famous sapphire color, while titanium can create