This place is only a few kilometres away from a place I went in 1993. Chihuahua, Mexico ! I was about to add it to my Google Maps journey record.
Here is the source of the above images, and the forum thread where I originally heard about these wonders. These are the images that stood out for me here, others show crystals the size of Greek columns, from floor to cave ceiling …. check out the links.
After consulting digg.com, I found that these crystals are now well known, as I hoped. I’m still not sure of the time scale here. Did they take a million years to form as I read somewhere ? Anyway, here is a good article about the discoveries, and the character who appears in the top photo here has a flickr page with full resolution pics of the cave. At least I think it’s him. He is certainly one of the people doing research for the mine company about preserving the find.