Citrine Geode (or Druzy Citrine)

Hardness: 7 on the Mohs scale. Color: Pale yellow to golden brown, often translucent. Luster: Vitreous (glassy). Crystal Structure: Hexagonal (trigonal crystal system). Cleavage: None (conchoidal fracture). Specific Gravity: 2.65.

Citrine is a variety of quartz. Natural citrine is relatively rare and is formed when amethyst or smoky quartz is heated naturally within the earth's crust by geothermal activity. The iron impurities within the quartz are what cause the yellow to orangish-brown color. Most commercial citrine is heat-treated amethyst or smoky quartz, a process that mimics natural geological heating. These druzy formations typically form within volcanic rocks or hydrothermal veins, where silica-rich fluids deposit quartz crystals over time. Geological Age: Formed over millions of years, often in association with igneous rocks.

Primarily used as a gemstone in jewelry, often cut into faceted stones, cabochons, or beads. Also popular as an ornamental stone and for mineral collecting, especially druzy specimens like the one shown. In metaphysical circles, it's known as the 'merchant's stone' or 'success stone'.

The name 'citrine' comes from the Old French word 'citrin', meaning 'lemon'. Much of the citrine available on the market today is actually heat-treated amethyst. Natural citrine is distinguishable by its paler yellow color compared to the more reddish-orange hue of heat-treated amethyst. A large amount of heat-treated amethyst comes from the Anahí Mine in Bolivia, which also yields natural amethyst and a unique amethyst-citrine bicrystal known as Ametrine.

To identify in the field: Look for its characteristic yellow to orangish color and vitreous luster. Its hardness of 7 means it can scratch glass. When found as a druzy, it appears as a sparkling layer of small, tightly packed crystals coating a surface, often within a geode or vug. Commonly found in Brazil (especially Rio Grande do Sul), Russia, France, Madagascar, and the USA (North Carolina, Colorado). For collectors, look for good color saturation and clarity, and well-formed, sparkly crystals in druzy specimens. Be aware that many deep orange/reddish-brown 'citrines' are heat-treated amethyst.