Citrine

Hardness: 7 on Mohs scale. Color: Yellow to golden-brown, often exhibiting zoning. Luster: Vitreous (glassy). Crystal Structure: Hexagonal (trigonal). Cleavage: None (conchoidal fracture). Specific Gravity: 2.65.

Citrine is a variety of quartz. Natural citrine is rare and typically forms when amethyst or smoky quartz is heated naturally within the earth, changing its iron impurities to a golden hue. Most commercial citrine is heat-treated amethyst or smoky quartz. It is primarily found in igneous and metamorphic rocks, often in pegmatites and hydrothermal veins. Its geological age varies greatly depending on the host rock, ranging from millions to billions of years.

Prized as a gemstone in jewelry due to its attractive color and durability. It's often cut into faceted gems, cabochons, and beads. Also used in ornamental carvings and as a collector's mineral specimen. Historically and metaphysically, it's associated with prosperity and positive energy.

The name 'citrine' comes from the French word 'citron,' meaning lemon, referring to its color. Natural citrine is much rarer than heat-treated amethyst, which is commonly sold as citrine. Heat-treated amethyst usually has a reddish-orange tint, whereas natural citrine tends to be a paler yellow to golden brown. Brazil is a major source of citrine.

Look for its characteristic yellow to golden-brown color and vitreous luster. It forms hexagonal prismatic crystals, often with visible striations on the prism faces. It can be distinguished from yellow topaz by its hardness (topaz is harder, 8) and crystal structure. In the field, it's found in granite pegmatites and hydrothermal veins. Common locations include Brazil, Bolivia, Madagascar, Russia, and the United States (North Carolina, Colorado).