Here at Littlefield Home we appreciate the natural beauty of Obsidian, which according to The Oregonian can be classified as “a dark natural glass formed when lava cools without crystalizing.” If you share this appreciation or are simply interesting in learning more about Obsidian, it’s handy to know the difference between Obsidian and its geological doppelgänger, Black Onyx. A Facebook post from May, 2011 entitled “How to tell the difference between black obsidian and black onyx” concisely juxtaposes the two minerals. According to the post’s unknown author, the difference depends solely on the presence or absence of crystallization.
The author explains that Obsidian does not possess a crystalline structure, due to heightened rate of lava-flow. Lacking angularity characteristic of crystalized surfaces, Obsidian instead resembles glass and for this reason is often called “volcanic glass.”
Onyx, on the other hand, does possess a crystalline structure because it was shaped by subterranean geological forces (rather than lava), before being mined. Onyx’s surface is visibly duller than that of Obsidian and in this way does not resemble glass.
Read more about the difference between Obsidian and Onyx here.
Learn about Obsidian sourcing and creation here in the USA here.