The Cave of Giant Crystals
Miners in Mexico broke into a cave of crystals up to 12 metres long, so hot that people could stay inside only minutes.
What was reported
In 2000, two brothers drilling in the Naica silver and lead mine broke into a cavern about 300 metres underground filled with enormous translucent crystals of selenite, a form of gypsum. The largest are around 12 metres long and weigh many tonnes.
Temperatures inside reach about 58 °C with near-total humidity, so scientists could enter only for short spells in cooling suits.
Explanations offered
The crystals grew over hundreds of thousands of years in mineral-rich water kept at a steady temperature by magma below. The mine's pumps kept the cave drained; when pumping stopped in 2015, it flooded again, and the crystals may resume growing. In 2017 scientists reported reviving microbes from fluid trapped inside them.
- When
- Found in 2000
- Where
- Naica mine, Chihuahua, Mexico
- Witnesses
- Miners, then scientists
- Status
- Explained
Famous cases are real, widely reported events. Each file sets out what witnesses said and the explanations that have been offered, without taking a side.