National Geographic has this article on the “Cave of Crystals” in Mexico. Very interesting and with the usual great photos.

Quick summary:

• The cave which is about 280m underground was discovered in 2000 during mining operations.
• It takes 20 minutes to get to the cave entrance driving a van along a winding mine shaft (see photo below)
• The cave is above a magma intrusion (a spot where magma comes close to the surface) and temperatures are about 45 Celsius!
• Because of the heat researchers must wear ice-cooled suits and use respirators blowing ice-cooled air. Even so they can only handle about 20 to 40 minutes.
• The crystals have been growing for the last 600,000 years in the cave which was originally water filled. The miners lowered the water table by pumping out the water and halted that growth.

This photo gives an idea of the size of the cave and the enormous crystals in it. Awesome stuff.

Getting to the entrance of the cave involves a 20 minute drive along the mine shaft

It is so hot in the cave that researchers must wear special ‘ice-suits’ in order to operate in the cave. They breath ice-cooled air through breathing packs and even so can only spend short periods in the cave.

You can view the rest of the photos here.

PS. National Geographic Magazine is an awesome publication – their articles are often fascinating and the photography is stunning. Their subscriptions are cheap and easy – I recommend subscribing.