Citrine is a variety of quartz (α-quartz) colored in a wide range of yellow color. The name is derived from the Latin word "citrus" which means a lemon, a lemon-like citron, distinctive yellow color.

Chemistry: SiO2;

Crystal system: Trigonal, Trigonally-trapezohedral crystal class (point symmetry group);

Color: Yellow, greenish-yellow, orange-yellow to orange, with smoky hue.

Yellow color is due to ferric Fe3+ impurities in the crystal structure.

Identification properties

Physical properties
Mohs hardness: 7
Density: 2.66±0.01 g/cm3
Cleavage: imperfect
Fracture: conchoidal
Optical properties
Optical character: anisotropic, uniaxial, positive
Refractive Index: no =1.544, ne =1.553
Birefringence: 0.009
Pleochroism: weak to intensive yellow tones
Dispertion: 0.013(BG)
Luster: vitreous

Inclusions and structural inhomogeneities

Gem basic treatments

Heat treatment (in the temperature range above 300°С) Removing the smoky and brownish hue

Inclusions and structural inhomogeneities

Synthetic or Imitation gem materials

Synthetic citrine for the jewelry industry is produced by several methods of hydrothermal technique, based on the principle of temperature gradient.

The most commonly encountered synthetic citrine is as follows:

  • colorless quartz, irradiation treated with the heat treatment followed;
  • surface-colored quartz;
  • quartz treated by "ion impregnation" - very rarely;
  • doublet: quartz + glass;
  • color glass

Inclusions and structural inhomogeneities