Citrine Quartz

Hardness: 7 (Mohs scale), Color: Yellow to brownish-orange (due to iron impurities), Luster: Vitreous (glassy), Crystal Structure: Hexagonal (often forms as prismatic crystals with terminations), Cleavage: None (conchoidal fracture), Specific Gravity: 2.65

Citrine is a variety of quartz. Natural citrine forms when amethyst or smoky quartz is heated naturally within the earth's crust, typically in pegmatite formations or hydrothermal veins. The heat alters the iron impurities within the quartz lattice, changing its color. Most commercial citrine is heat-treated amethyst. Geological Age: Varies depending on the host rock, but quartz is a ubiquitous mineral found in rocks of all ages, from Precambrian to Cenozoic.

Industry: Not widely used in industry beyond its ornamental value. Jewelry: Highly prized as a gemstone for rings, necklaces, earrings, and bracelets due to its warm color and durability. Construction: Not used directly in construction, but quartz is a component of many building materials. Collecting: Valued by mineral collectors for its crystal forms and color.

The name 'citrine' is derived from the Old French word 'citrin', meaning yellow. Natural citrine is quite rare, making heat-treated amethyst a common substitute in the market. It is often associated with positive energy and is considered a 'success stone'. Brazil is a major source of natural citrine and amethyst for heat treatment.

Identify in the field: Look for transparent to translucent, yellow to orange-brown hexagonal crystals. Can be distinguished from yellow topaz by its hardness (topaz is 8) and often by its crystal habit. Commonly found: Brazil (especially Minas Gerais), Russia, France, Madagascar, and the USA (North Carolina). Collectors should be aware that many 'citrine' specimens are heat-treated amethyst, which can often be identified by a reddish-brown tint not typically found in natural citrine. Natural citrine usually has a paler, more even yellow color.