Produced from felsic lava, obsidian is rich in the lighter elements such as silicon, oxygen, aluminium, sodium, and potassium. It is commonly found within the margins of rhyolitic lava …

Dec 9, 2025 · Obsidian is an igneous rock occurring as a natural glass that is formed by the rapid cooling of viscous lava from volcanoes.

Nov 10, 2025 · Obsidian is a naturally occurring volcanic glass, classified as an extrusive igneous rock that forms from the rapid cooling of molten material erupted from a volcano. Unlike most …

Aug 29, 2025 · It forms from molten rock that cools very quickly, preventing the formation of distinct mineral crystals. This geological origin gives obsidian its characteristic glassy texture. …

Most obsidians have a composition similar to rhyolite and granite. Granites and rhyolites can form from the same magma as obsidian and are often geographically associated with the obsidian. …

Jul 12, 2025 · Obsidian is an igneous rock formed when lava is ejected from a volcano. The rock cools so quickly is becomes black glass.

Obsidian is an "extrusive” rock, which means it is made from magma that erupted out of a volcano. If it was an igneous rock that formed from magma underground and did not erupt, it …

Jul 17, 2025 · How is obsidian formed? Obsidian is a naturally occurring volcanic glass formed when felsic lava extruded from a volcano cools very rapidly with minimal crystal growth, …

Jan 23, 2025 · Obsidian is a volcanic glass that’s formed when molten lava cools suddenly. Is it a mineral? The answer lies in how it’s formed. Pin this post to save this information for later. …

Sep 28, 2024 · Obsidian is made primarily of silica, the same material found in quartz and glass, which explains its smooth, shiny appearance. It forms when hot lava cools so rapidly that …