Quartz crystals have been mined in the east central part of Montgomery County since the early 1900s.
The mineral, quartz, (Sio2 Silicon Dioxide) is one of the most common minerals on the surface of our planet. It occurs in a greater variety of forms than any other mineral. The quartz crystal found in Montgomery County is of crystalline or vitreous type in which actual crystals can be seen without the aid of 
a microscope. Quartz has no cleavage; the fracture is conchoidal--the type of swirl one sees when a bottle is broken.
On Moh's Scale of Hardness the hardness of quartz is seven (with diamond being ten.) Quartz has a specific gravity of 2.65 and is vitreous to greasy or dull in luster.
It is the way crystals are formed that makes them special. Silicon and oxygen, the components of quartz, are the same elements as in common sand; but crystals of this compound are relatively rare. Crystals grow from silicon that has been dissolved in superheated water--which today is still boiling around Hot Springs, Collier Springs, Norman, and Mount Ida. As the water cools, the silicon recombines with oxygen, forming hexagonal structures of perfect molecular alignment, according to David Lebow.
Small quantities of quartz crystals are found in several places on earth but sizable deposits are rare. Russia lets little be known of her mineral resources. That leaves Madagascar, Brazil and the Ouachita Mountains with enough high quality quartz crystal to warrant mining.
In Arkansas, the greatest concentration of high quality quartz crystals occurs along a twenty-five to fifty mile wide band stretching between Hatfield (Polk County) to North Little Rock. The highest production takes place in Montgomery County with the greatest concentration of high quality specimens in the environs of Mount Ida. Thus, Mount Ida has been declared the "Quartz Crystal Capital of the World."