obsidian: Quick Facts

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obsidian boulders

Eight labeled rock samples are shown, including black glassy obsidian, speckled porphyry, striped calico sandstone, shell-filled coquina limestone, coarse breccia, layered banded gneiss, pale green fibrous talc schist, and greenish serpentine.

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Topics

volcanic glass extrusive rock pumice basalt perlite trachyte rhyolite phonolite diabase andesite pitchstone spilite

Basalt sample returned by Apollo 15, from near a long sinous lunar valley called Hadley Rille. Measured at 3.3 years old.

(Bed) Rocks and (Flint) Stones