Bok
09-12-2011, 08:18 PM
Slow-growing crystals formed over thousands of years in Mexico cave
More... (http://www.sciencenews.org/view/generic/id/334299/title/Natures_crystal_palace)
More... (http://www.sciencenews.org/view/generic/id/334299/title/Natures_crystal_palace)