The rock crystal Quartz, is the most common gem variety of quartz crystal, and is formed from the two most abundant elements in the earth's crust: silicon and oxygen. For centuries early civilizations believed that these "pinhead size to nearly a meter in diameter" rock crystals were permanently frozen ice.
Quartz's high thermo-conductivity, which makes it feel cool to the touch, may have added to this belief. Regardless of what early people may have believed, historical records show the use of rock crystal for decoration and jewelry for at least 4,000 years. Tools and weapons were made from rock crystal long before it was used for decoration and jewelry.
During the late 1980's and early 1990's, metaphysical uses and applications of rock crystal resulted in an increase in its production and processing. The metaphysical market used raw crystal in jewelry, person power and healing devices, and as charms. Additionally, spheres, sculls, pyramids, and other metaphysical objects were made from rock crystal.
During the height of the trend, these uses accounted for 40% or more of the rock crystal consumed in the United States and also resulted in price increases for most of the crystals.
Today, the metaphysical market has declined from its peak and appears to have stabilized at about 15% to 20% of total rock crystal consumption.