Citrine is the yellow or golden yellow variety of quartz. The yellow coloration, due to the presence of iron, is also responsible for the name, derived from the word “citrus”. Natural citrine is usually a pale yellow, but rare; most citrine on the market is heat-treated amethyst.
Gem-quality citrine is extremely rare. The best material is found in Brazil, Spain, Madagascar, and the former USSR.
Citrine has been used to imitate topaz and was once called Brazilian topaz.
Silica (Silicon Dioxide) SiO
Colors / Varieties:
Crystal System / Forms:
2.63 - 2.68
Cleavage / Fracture:
No distinct cleavage / conchoidal to uneven fracture.
; Uniaxial positive. May exhibit a bull's eye optic figure (quartz rotates the plane of polarisation parallel to the c-axis).
Refractive Index / Birefringence:
1.544 - 1.553 / 0.009. Range: 1.535 - 1.560
Yellow / Slightly paler yellow
Liquid and two phase, color zoning, negative crystals, zebra-stripe finger prints (structural), crystal inclusions, green
mica flakes / platelets in aventurine quartz,
needles in sagenitic quartz. Brazil law twinning is seen in natural quartz.
Cause of Color:
Trace of Iron (Fe
Piezoelectric: develops an electric charge when pressure is applied.
Pyroelectricity: develops an electrical charge when heated.
Diasterism in star variety (star visible in reflected and transmitted light).
Identification: type of twinning, seed plate, breadcrumb inclusions, Raman / infra-red spectroscopy.
Simulants (with separation tests):
fluorescence, inclusions, doubling), synthetic citrine (inclusions, infra red spectroscopy),
(optic figure/sign, inclusions,
Very widespread, in pegmatite.
Brazil, India, South Africa, Namibia, Madagascar, Zambia, Sri Lanka.
Cuts & Uses:
Facetted cuts, cabochon, carvings, beads, etc.