Crystals from the United States

Turquoise from the American Southwest has been worked for more than a thousand years by Indigenous peoples, and Navajo and Zuni jewellery made it an emblem. Nevada and Arizona long led production; many historic mines are now closed or exhausted, which explains the price of natural American turquoise.

The United States has also given names to several stones: kunzite, described in 1903 from Californian crystals and named after gemmologist George F. Kunz, and unakite, named after the Unaka Mountains between North Carolina and Tennessee. In Maine, the country's first tourmaline was found in 1820 at Mount Mica.

Howlite, white veined with grey, is often dyed blue to imitate turquoise: a very cheap bead sold as « turquoise » deserves a question to the seller. Fire agate, found in Arizona as well as Mexico, owes its iridescent flashes to thin layers of iron oxide within the chalcedony.