When you first approach the crystal digging area on the west end of the Great Salt Plains, it looks like beautiful white water. Well, The Great Salt Plains in Alfalfa County, in northwestern Oklahoma, is the only place in the world where hourglass-shaped selenite crystals are found. Thousands of thousands years ago this area was covered by a large inland sea. As the time passes the sear was ultimately cut off and the water disappeared away, leaving behind thick layers of salt that were consequently covered by dirt and erosion from nearby mountain ranges. Hence as groundwater upsurges to the surface through the salt-saturated sand, it takes salt along with it and sums them on the surface as a thin crust. It is the concentrated saline solution uniting with gypsum that stimulates the growth of selenite, a crystalline form of gypsum. Therefore, these crystals are found buried only a few feet below the surface, under an area that’s 11,000 square miles in size. Moreover, the crystals may form very quickly, as when substantial rains or floods bring great quantities of freshwater to the plains, some of the selenite crystals may go back into solution until conditions are right for recrystallization.
Moreover, Gypsum crystals are affected by the surroundings they grow in. Ultimately the finer soil result in the clearer the crystals. The color of crystals found on the Great Salt Plains are chocolate brown due to the presence of iron oxide in the soil, and since these crystals form in wet soil, sand and clay particles are included within the crystal. These particles often form an "hourglass" shape inside the crystal. This hourglass shape is exclusive to selenite crystals that produce on the Salt Plains of northwest Oklahoma. Furthermore, aside from hourglass-shaped crystals, single crystal blades, penetration twins, and clusters are also found here. Therefore, some crystals that have been found here measured up to 7 inches long, and multifaceted combinations weighed as much as 38 pounds. Since these crystals are so exceptional, they were selected as the State Crystal of Oklahoma in 2005 and Great Salt Plains itself is a protected State Park. But, every year starting from April and October, the west edge of the Great Salt Lake is opened up digging, enticing rock enthusiasts from all over America and beyond. Therefore collectors are well permitted to take up to ten pounds of crystals, but for personal use only. Make sure selling of crystals is illegal.