Blue Aventurine Rosary Bracelet Crucifix - Miraculous Medal:Antique Gold this iron content is not

this iron content is not present throughout the whole gemstone

The chatoyancy of the stone is caused by altered amphibole (an inosilicate) fibers that have over time become limonite

and crackled clear color

Obsidian is formed from quickly cooling magma

These lustrous metallic tints

Blue Aventurine Rosary Bracelet Crucifix - Miraculous Medal:Antique Gold this iron content is notAventurine is a form of quartz, characterized by its translucency and the presence of platy mineral inclusions that give a shimmering or glistening effect. This shimmering effect is called aventurescence. Chrome bearing fuchsite (a variety of muscovite mica) is the classic inclusion, and gives a silvery green or blue sheen. These blue aventurine beads course and it ranges from a light blue through to a quite strong blue color.