Quartz crystals, beautiful and relatively inexpensive, occur naturally in several locations throughout the United States. Quartz is the second-most abundant mineral in the earth's crust and comes in several varieties, some of which are gemstones.
Spruce Pine Gemstone Mine
The Spruce Pine Gemstone Mine, located in the Blue Ridge Mountains of North Carolina, first opened in 1810. As its name implies, it is known for gemstones and produces quartz crystals of extremely high purity.
Mount Ida, Arkansas
Mount Ida, Arkansas, bills itself as the quartz crystal capital of the world. It is home to several open-pit mines, in which crystals are found in clay deposits around crystal veins. Several sites allow public digging, though with some restrictions.
Amador and Calaveras Counties, California
Amador and Calaveras counties in California produce large quantities of high-quality crystal along a steam channel in the Mokelumne Hill area.
Herkimer County, New York
Herkimer County, New York, is also known for a quartz-crystal belt that produces "Herkimer diamonds." No commercial mining of quartz crystals in this area is currently in progress, with the crystals being hunted by individual rock hounds.