Natural 14.15cts obsidian eye rainbow cabochon 21x16 mm loose gemstone s28911

Rainbow Obsidian Eye

Formed as an extrusive igneous rock, Obsidian is a naturally occurring volcanic glass. When felsic lava is ejected from a volcano and after it cools down quickly with minimal crystal growth then obsidian is produced. Obsidian is commonly found in the places where rhyolitic lava eruptions happen. Obsidian is a parent material formed from quickly cooled lava and it is not a mineral, but a mineral-like, as it is not crystalline as well as its composition is too variable to be classified as a mineral. Well, it can be classified as a mineraloid. Around 70 per cent silicon dioxide (SiO2) is present in Obsidian. Usually, pure obsidian is dark in color but due to the impurities the color may vary. With the presence of iron the obsidian may appear b...