QUARTZ (var. AGATE, subvar. FIRE)

HISTORY, NAME, LOCALITIES: The fire subvariety of agate, known since antiquity, is a valuable semiprecious gemstone. The name “agate,” pronounced AHH-git (rhymes with “tag it”), comes from the ancient Greek name for Italy’s Drillo River in Sicily, an important early source. The fire subvariety is named for its fire-like flashes of iridescent color caused by included particles. Fire agate is found in Mexico and the western United States (Arizona, Oregon, Nevada, California, New Mexico).

MINERALOGY, PROPERTIES, OCCURRENCE: Agate, a variety of microcrystalline quartz [silicon dioxide, SiO₂], is a tectosilicate or framework silicate with a Mohs hardness of 6.5-7.0, a conchoidal fracture, and a specific gravity of 2.62-2.65. It forms as nodules, vein fillings, or interior linings of geodes. Fire agate is translucent; it is distinguished by a reddish-brown base color that is highlighted by flashes of iridescent reds, oranges, greens, and golds caused by light interference within reflections from included particles of hematite and limonite.

METAPHYSICAL PROPERTIES, LORE, USES: Medieval alchemists believed that fire agate contained the essence of fire. According to modern metaphysical practitioners, fire agate provides the courage to take risks, promotes decisive action in confusing situations, and helps to reconnect goals to one’s deepest desires. Fire agate is cut and polished into cabochons for use in jewelry. It has no technological uses.

COLLECTORS’ INFORMATION: Cut-and-polished fire agate is widely collected for its beautiful flashes of iridescent colors. It is one of the most valuable forms of agate.