Pitchstone

Pitchstone ridge "An Sgurr", Isle of Eigg, Scotland

Pitchstone is a dull black glassy volcanic rock formed when lava cools swiftly. It is similar to but coarser than obsidian.

The ridge of An Sgurr on the Isle of Eigg was originally formed as a lava flow in a valley. Pitchstone is very resistant to erosion.

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This page was last modified 23:08, 26 March 2008 by Wikipedia user PipepBot. Based on work by Wikipedia user(s) Afluegel, Pegship, Butsuri, Hooperbloob and CarolGray and Anonymous user(s) of Wikipedia.
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