megacrystals in naica mine

There are megacrystals in the naica mine in mexico. They are many feet in size. Interesting thing is that these crystals are made out of gypsum. This is the substance in drywall plaster and it is quite common. However, never would many believe there could be these megacrystal marvels of nature that are giants in size. Hope one day to visit the naica mine.