Mahogany Obsidian Rosary Bracelet Crucifix - Miraculous Medal:Antique Gold How originally called the stone

How originally called the stone silicoborocalcite

The schiller effect results from the lamellar (layered) structure of this feldspar – light enters the stone and is refracted back and forth between layers

Renaissance painters ground it for brilliant ultramarine pigment

forming this highly porous rock

it actually has very little relation with other varieties of Jade

Mahogany Obsidian Rosary Bracelet Crucifix - Miraculous Medal:Antique Gold How originally called the stoneObsidian has been used as a gemstone since antiquity. Imagine a fine piece of mahogany furniture that gleams like glass that's mahogany obsidian. Obsidian is a naturally occurring volcanic glass that's created when lava rich in feldspar and quartz is cooled too rapidly for crystals to form. It's not considered to be a true mineral because its composition is too complex and it doesn't have a crystalline structure. In addition to its decorative use,