• Exhibition Text

    • Obsidian is a volcanic glass, a comparatively rare and crystal-poor form of rhyolite, the most silica-rich lava. It forms when lava is quenches, or rapidly cooled. Obsidian is a major component of Glass Mountain.

      Provided by Jeff Dinnel, Tionesta, California

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  • For Educators

    • Topic: Earth Science

      Subtopic: Volcanoes

      Keywords: Medicine Lake (Cal.), Rhyolite, Volcanoes, Lava, Volcanism

      Audience: General