Fulgurite is scientific Latin for "lightning stone." Fulgurites are made when lightning strikes the ground. When a bolt strikes loose sand, it vaporizes a thin wormhole and melts the zone around it, creating an instant froth of natural glass. These fulgurites can be meters long, but they're fragile, and what you see in rock shops are usually small pieces a few centimeters long and as light as pumice. Sometimes a fulgurite forms in solid rock, a skin of natural glass. The glass made from pure quartz has the mineral name lechatelierite
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