Sieber Agate 10mm Round AA Grade - 15-16 Inch 48hr_01202026 Ethiopian Opal typically occurs in

Ethiopian Opal typically occurs in brown

Many stones in the Russian crown jewels from the 17th century which were thought to be rubies are actually red Tourmaline

By soaking the stone in a non-toxic chemical solution

A cryptocrystalline Chalcedony

It is extremely tough and resistant to fracture and has been used to make choppers and blades since Neolithic times

Sieber Agate 10mm Round AA Grade - 15-16 Inch 48hr_01202026 Ethiopian Opal typically occurs inSieber agate is not a true agate but rather a glassy, dark blue grey or green copper slag that formed during ancient copper smelting in Germany, specifically from the Siebertal area. This historical "ancient slag" has a naturally swirling, intricate appearance resembling agate due to silica and mineral inclusions from the smelting process. It is a rare and collectible material known for its lapidary qualities, similar to obsidian, and is sometimes