Cave of the Crystals or Giant Crystal Cave is a cave connected to the Naica Mine 300 metres ft) below the surface, in Naica, Chihuahua, Mexico. The main chamber contains giant selenite crystals (gypsum, some of the largest natural crystals ever found.
Crystal Caves in Mexico. This cave features some of the largest selenite crystals in the world. If you do plan to visit, note that the temperature in these caves often gets up to with percent humidity.
Rainbow Moonstone is as equally appealing to me as its closest relative, Labradorite. An intriguing cabochon of Rainbow Moonstone, from India. Cut from hard-to-find rough, Romans named it so because they thought it was made of moonlight.