Citrine
Quartz var. Citrine · Semi-Precious Gemstone
Crystal System
Trigonal, with a microcrystalline or macrocrystalline quartz habit, often occurring in prismatic crystals, massive forms, or geode linings.
Mineral Group
Silicates, specifically Tectosilicates
Chemical Formula
SiO2
Formation Process
Hydrothermal and igneous processes, typically crystallizing from silica-rich solutions at low to moderate temperatures, or through natural irradiation of smoky quartz.
About This Crystal
A translucent to transparent specimen exhibiting a warm yellow to golden-brown coloration with vitreous luster, showing internal crystalline facets and interlocking quartz structures.
Physical Characteristics
Color ranges from pale yellow to brownish orange; white streak; no cleavage; conchoidal fracture; specific gravity of approximately 2.65; brittle tenacity; exhibits strong piezoelectric properties.
Optical Properties
Singly refractive to anomalously doubly refractive, uniaxial positive, with a refractive index of 1.544 to 1.553 and weak birefringence of 0.009.
Hardness & Durability
Origin Region
Brazil, Madagascar, Bolivia, Spain, and the Ural Mountains in Russia. Forms in pegmatites and hydrothermal veins.
Hardness & Durability
Mohs hardness of 7, excellent durability with no cleavage, making it very suitable for everyday jewelry use such as rings and pendants.
Care & Maintenance
Clean with warm soapy water and a soft brush. Avoid prolonged exposure to direct sunlight which can cause the color to fade. Do not expose to harsh hydrofluoric acid.
Rarity & Value
Common to moderately rare for natural, unheated deep-colored stones. Value depends on color saturation, clarity, and size. Most commercial citrine is heat-treated amethyst.
Special Characteristics
Strong piezoelectric and pyroelectric properties; often displays color zoning and can be confused with heat-treated amethyst.
Lore & History
Historically known as the 'merchant's stone' for its association with prosperity and wealth. Used in ancient jewelry and ornamentation since the Hellenistic period.