Information AboutPitchstone |
| CATEGORIES ABOUT PITCHSTONE | |
| igneous rocks | |
| volcanology | |
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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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