Take a look at this hollow tube made of quartz. What is its story?
Answer:
This is a fulgurite, a tube of melted sand formed by a lightning strike. If the bolt is hot enough (more than 2950°F), it will melt quartz sand. The melted liquid soaks into the surrounding sand, and cools, to form a hollow tube. The outside of the tube is rough, made up of partially melted sand grains.
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