Albite Value, Price, and Jewelry Information

FELDSPAR: Albite, Sri Lanka (4.6), New Mexico (3.9). Photo © Joel E. Arem, PhD, FGA. Used with permission.

Albite

Albite, usually colorless but sometimes yellow, pink, gray or reddish. Translucent albite is sometime colored green by chrome jadeite. It is also a component of trapiche emeralds.

Albite Information

Data Value
Name Albite
Is a Variety of Feldspar
Varieties Peristerite
Colors Colorless, white, yellow, pink, gray, reddish, greenish.
Hardness 6 -6.5
Fracture Uneven to conchoidal
Cleavage Perfect one direction; very good; imperfect
Formula Ab100, Ab90
Crystallography Triclinic. Twinned; platy crystals.
Refractive Index 1.527-1.544
Birefringence 0.008-0.011
Dispersion 0.012
Luminescence Usually none; may be whitish in LW, lime green in X-rays (Kenya).
Absorption Spectrum Not diagnostic.
Pleochroism None.
Optics α = 1.527; β = 1.531; γ = 1.538. Biaxial (+); 2V = 77°. See "Comments" for information on varieties.
Optic Sign Biaxial +
Luminescence Present Yes
Luminescence Type Fluorescent, UV-Long, X-ray Colors
Luster Vitreous to pearly.
Specific Gravity 2.57-2.69
Transparency Transparent to opaque.

Comments

Translucent albite is sometimes found that is colored a rich green by inclusions of chrome-rich jadeite. Albite is sometimes intergrown with emerald, especially in the strange hexagonal skeletal crystals known as trapiche emeralds. Facetable albite from Madagascar has indices: a = 1.530-1.531; β= 1.532-1.533; γ= 1.539-1.540; birefringence 0.009-0.010; density 2.62. Small faceted gems are fairly rare, almost always from the tips of cleavelandite crystals. Albite gems are colorless in most cases and not exciting to look at. Albite moonstones are known from many localities (discussed below).

Name

Albite comes from the Latin albus, meaning white, because the mineral is usually white.

Occurrence

Albite usually forms at low temperatures; it is common in pegmatites, granite, and other igneous rocks, various metamorphic rocks, also marbles.

  • Essex County New York.
  • Ontario, Canada; Quebec, Canada; Madagascar; Austria.
  • Rutherford Mine, Amelia, Virginia: fine colorless albite, facetable, large; crystals are platy variety known as cleavelandite.
  • Upson County, Georgia: moonstone.
  • South Dakota: cleavelandite.
  • Brazil: cleavelandite.
  • Kenya: colorless crystals, some with blue or yellow tinge.
  • (Indices: 1.535/1.539/1.544; S.G. 2.63). Many other localities worldwide.

Stone Sizes

Clean gems are usually in the 1-3 carat range, from cleavelandite crystals. Catseye gems up to about 50 carats are known.

  • Royal Ontario Museum (Toronto, Ontario, Canada): 12.25 (catseye, Burma).
  • Devonian Group (Calgary, Alberta, Canada): 11.13 (cateye, white).
by Joel E. Arem, Ph.D., FGA