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Obsidian

Pictures of Igneous Rock Types

Obsidian is an extrusive rock: lava that cooled without forming crystals, giving it a glassy texture. Learn more about obsidian in the obsidian picture gallery.

Volcanic glass

Photo (c) 2007 Andrew Alden, licensed to About.com (fair use policy)

Other galleries:
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Geologic Features and Processes
Glaciers and Ice
Landforms
Minerals
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Gallery Index: Igneous Rock Types

Reader Submissions: My Igneous Rock

Read Submissions (8) Show Us Your Photo

Igneous Rock Basics

About Igneous Rocks Volcanic (Extrusive) Rock Types Igneous Rock Classification Diagrams

Details of Igneous Rocks

Igneous Rock Textures Obsidian Gallery Phenocryst Gallery

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Andrew Alden

Andrew Alden
Geology Guide

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