Quartz

Quartz (SiO2) is one of the most abundant minerals in the Earth's crust, crystallizing in the trigonal system and prized by collectors for its clarity, habit diversity, and huge range of color varieties. Classic forms include colorless rock crystal, purple amethyst, yellow citrine, gray-brown smoky quartz, black morion, and pink rose quartz, each with its own dedicated following among mineral collectors.

Typical worldwide localities include the giant clusters of Minas Gerais in Brazil, the gem-clear points of Mount Ida and Hot Springs in Arkansas, and the doubly-terminated "Herkimer diamonds" of Herkimer County, New York. Alpine-cleft smoky quartz from the Swiss Alps and Mont Blanc massif, amethyst geodes from Artigas in Uruguay, and the smoky-to-amethyst combinations of Brandberg in Namibia are equally sought after.

Exceptional pieces push collector interest further: lustrous black Tibetan quartz, elegant Japan-law twins, needle-included rutilated quartz, and tourmalinated quartz studded with black tourmaline crystals. Layered growth phantoms, faden quartz from Pakistan's Baluchistan region, and scepter formations add further variety. This combination of chemical simplicity and near-infinite crystallographic expression is exactly why quartz remains a cornerstone of any serious mineral collection.