When the formation of the volcanic glass is free from inclusions, the end result is clear black obsidian. The dark color of obsidian is largely due to the presence of iron and magnesium. It doesn’t have the typical cleavage of other gemstones, plus its conchoidal fracture and acute edges when broken allow it to form very sharp and smooth edges. See it here.Īs a type of volcanic glass, obsidian is hard, amorphous, and brittle. See it here.īecause obsidian is only found in locations that have experienced volcanic eruptions, the most common mining sources for this gemstone are, in alphabetical order, Argentina, Armenia, Azerbaijan, Canada, Chile, Georgia, Greece, El Salvador, Guatemala, Iceland, Italy, Japan, Kenya, Mexico, New Zealand, Peru, Scotland, Turkey, and the United States.Īs a volcanic glass, obsidian resembles a mineral but it’s not a true mineral because its composition is too complex and lacks the typical mineral crystalline structure. That, together with the other specifics of the chemical content allows a high viscosity, which is what allows the lava to form into glass. The reason is so that these flows are rich with silica, and obsidian is typically made of 35% – 80% silica. The most common place to look for obsidian rocks is in the margins of the rhyolitic lava flows that are otherwise known as “obsidian flows”. Such cooling typically happens rapidly after a volcano becomes inactive. See it here.īlack obsidian, like other types of obsidian, is a naturally produced volcanic glass formation that results from the cooling off of felsic lava. ![]() What is Black Obsidian? Black Obsidian Arrowhead Necklace.
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