Citrine

Hardness: 7 on the Mohs scale. Color: Pale yellow to golden brown, often a vibrant golden-orange or yellowish-green. Luster: Vitreous (glassy). Crystal Structure: Hexagonal (trigonal system), typically forming prismatic crystals with striations perpendicular to the long axis and pyramidal terminations. Cleavage: None (conchoidal fracture). Specific Gravity: 2.65.

Citrine forms in igneous and metamorphic rocks. Natural citrine is relatively rare and is typically created when amethyst or smoky quartz is heated naturally within the earth. Most commercially available citrine is heat-treated amethyst or smoky quartz, changing its color to yellow or orange. This heating can occur naturally by geological processes or artificially. It is found in hydrothermal veins and pegmatites.

Citrine is highly valued as a gemstone and is widely used in jewelry (rings, necklaces, earrings, bracelets). Larger specimens are popular for mineral collections and decorative objects. It is sometimes used as a birthstone for November and is associated with prosperity and positive energy. Due to its hardness, it is durable for everyday wear.

The name 'citrine' comes from the Old French word 'citrin,' meaning 'yellow,' which is derived from the Latin 'citrus.' Unlike many other gemstones, natural citrine is not common. Much of the citrine on the market is heat-treated amethyst. Natural citrine generally has a paler, more subdued yellow color, whereas heat-treated amethyst tends to have a reddish-orange tint. Brazil is a major source of both natural and heat-treated citrine. Some large quartz crystals can form, weighing several hundreds of pounds.

In the field, look for hexagonal prismatic crystals (often with pyramidal terminations) with a yellow to yellowish-brown color. Its hardness (scratches glass) and vitreous luster are key identifiers. It's often found in igneous environments such as granite and pegmatite intrusions, and also in metamorphic rocks. Common locations include Brazil (Rio Grande do Sul), Russia (Ural Mountains), France, Madagascar, and the USA (North Carolina). When identifying, look for its characteristic color and crystal habit. If it's a deep reddish-orange, it's likely heat-treated amethyst. Natural citrine tends to be less saturated in color.