following photos are from Crystal Cave of Giants
This website also has a good article on the discovery and the geology of these giant
gypsum (selenite) crystals from a large cave in Naica, Chihuahua, Mexico.
photos are being posted here because everyone interested in geology should know
The following photos have been corrected in terms of contrast and lighting from the original photos.
These crystals are really this large! Photos of the miners were not glued to a photo of a geode.
It is really hot in the cave. Notice the miners sweating.