After a week of depressing news and heavy-duty blogging, I wanted to end the week on a lighter note and to focus on nature's wonder. The BBC just released this amazing video of the Naica cave in Mexico. The cave was accidentally discovered in 2000 when silver miners broke through the wall of a selenite geode ... a very, very BIG geode.

The cave contains some of the largest crystal formations ever discovered, and due to the 100 percent humidity found in the cave (which results in water condensing on your lungs in just a matter of minutes) scarcely anyone, even geologists, have had the opportunity to visit the magical underground crystal palace.

Professor Iain Stewart reminds us how little we truly know about the ground beneath our feet:

"We know more about the outer edges of the solar system than we do about the first kilometre of the Earth's crust. As we learn more about the crust, we can be sure that there will be discoveries even more spectacular than Naica. I just hope I'm around to see them."
Subterranean spectacle: The crystal cave
BBC takes you on a video tour of the breathtakingly beautiful (and deadly) Naica Crystal Cave in Mexico.