Obsidian (/ əbˈsɪdi.ən, ɒb -/ əb-SID-ee-ən ob-) [5] is a naturally occurring volcanic glass formed when lava extruded from a volcano cools rapidly with minimal crystal growth. It is an igneous rock. [6] . Produced from felsic lava, obsidian is rich in the lighter elements such as silicon, oxygen, aluminium, sodium, and potassium.

Obsidian is an igneous rock that forms when molten rock material cools so rapidly that atoms are unable to arrange themselves into a crystalline structure. It is an amorphous material known as a " mineraloid ."

4 days ago · Obsidian is an igneous rock occurring as a natural glass that is formed by the rapid cooling of viscous lava from volcanoes. Where is obsidian found? Some of the best-known occurrences of obsidian are at Mount Hekla in Iceland, the Eolie Islands off the coast of Italy, and Obsidian Cliff in Yellowstone National Park, U.S.

Nov 8, 2023 · Obsidian is an extrusive igneous rock. It is occurring as a natural glass formed by the rapid cooling of viscous lava from volcanoes. Result of this formed, glass occupies more than 80 % and that have seeming conchoidal fracture and vitreous luster. It usually colours dark, black, grey-black to grey.

Mar 5, 2025 · As an amazing volcanic glass, obsidian comes in many different types. When you explore them, you’ll realize the incredible variety and value of obsidian, as they are used for everything from jewelry to ancient tools. Black obsidian is, as its name suggests, usually deep black and super shiny, like a piece of the night sky.

Obsidian is a naturally occurring volcanic glass formed when felsic lava cools rapidly without crystallizing. Its smooth glassy texture and sharp edges have made it highly valued by ancient cultures for tools and weapons, and today it remains popular for decorative objects and jewelry.

Jun 23, 2023 · Obsidian forms from rapid quenching by water or air of highly viscous, silica-rich rhyolitic magma low in volatiles on or near the Earth’s surface. However, it can also form as an intrusive rock on the edges of dikes, rhyolitic flows, plugs, necks, lenses, or sills.

Obsidian consists of about 70 percent or more non-crystallized silica (silicon dioxide). It is chemically similar to granite and rhyolite, which also were originally molten. Because obsidian is not comprised of mineral crystals, technically obsidian is not a true "rock."

Jan 23, 2025 · Obsidian is a volcanic glass formed when molten felsic lava cools suddenly. Is it a mineral? The answer lies in how it’s formed. Explore obsidian and its types.

Jan 11, 2024 · Obsidian is a naturally occurring volcanic glass and one of the most striking types of igneous rocks. This article delves into what obsidian is, its formation and composition, the different...