Citrine (Heat-Treated Amethyst)
Quartz var. Citrine · Semi-Precious Gemstone / Mineral Specimen
Crystal System
Trigonal; typically occurs in hexagonal prismatic habits but often found as crystalline masses or point shards in trade. This specimen shows a massive to broken crystalline habit.
Mineral Group
Silicates (Tectosilicate)
Chemical Formula
SiO2 (Silicon Dioxide) with trace iron impurities (Fe3+)
Formation Process
Principally hydrothermal in igneous remnants. While natural citrine forms via geothermal heat, this specific deep orange/burnt-white specimen is likely formed by the 'anthropogenic' heat treatment of amethyst at approximately 480-560°C.
About This Crystal
A translucent to opaque crystalline shard featuring a gradient from white/milky quartz at the base to a deep 'burnt' orange or amber hue at the tips. It exhibits a vitreous to waxy luster with internal fractures and a jagged surface texture.
Physical Characteristics
Color: Pale yellow to deep honey-orange; Streak: White; Cleavage: None (indistinct); Fracture: Conchoidal to uneven; Specific Gravity: 2.65; Fluorescence: Usually inert under UV light; Magnetism: None.
Optical Properties
Refractive Index: 1.544–1.553; Birefringence: 0.009; Pleochroism: Very weak; Optical Character: Uniaxial positive. This specimen shows the characteristic opacity resulting from heat-induced internal stress.
Hardness & Durability
Origin Region
Mainly Rio Grande do Sul, Brazil; also Uruguay. Natural citrine is found in Madagascar and Russia, but heat-treated varieties (as shown) are predominantly Brazilian.
Hardness & Durability
Mohs Hardness: 7; Toughness: Good; Stability: Stable to light, but color can fade if exposed to extreme heat or prolonged direct sunlight over many years. Excellent for all jewelry types.
Care & Maintenance
Wash with warm soapy water. Avoid ultrasonic cleaners if the stone has heavy internal fractures (common in heat-treated pieces). Store away from direct sunlight to prevent potential color fading.
Rarity & Value
Common and affordable. Value is determined by color intensity. 'Made' citrine (treated amethyst) is much less valuable than rare, naturally occurring citrine which is pale lemon-yellow rather than deep orange.
Special Characteristics
Displays 'burnt' tips characteristic of baked amethyst; often contains internal 'veils' or 'feathers' (fractures) caused by the rapid expansion of water inclusions during the heating process.
Lore & History
Historically known as the 'Merchant's Stone' and associated with prosperity and success. In modern crystal practices, it is linked to the Solar Plexus chakra. While used in jewelry since the Hellenistic Age in Greece, most commercial 'citrine' since the 18th century has been produced by heating amethyst.