Tumbled Obsidian / 20-50mm AVG - 1 KILO LOT

Quantity: 1 kilogram

Average size range: 20 to 50 millimeters

Obsidian is not a gemstone, but instead a kind of glass that forms when volcanic lava rapidly cools in the open air without forming any specific crystalline structures. When polished, obsidian can occasionally exhibit a gold, silver, or rainbow sheen depending on any included minerals.