Beryl is a beryllium aluminium silicate with the chemical formula Be
3Al 2(SiO 3) 6. The hexagonal crystals of beryl may be very small or range to several meters in size. Terminated crystals are relatively rare.
Pure beryl is colorless, but it is frequently tinted by impurities; possible colors are green, blue, yellow, red, and white.
Beryllium Aluminium Silicate (Be
; Trace elements are Cr, V, Fe, Mn, etc.
Colors / Varieties:
Emerald (Cr/V/Fe) Green - Green Beryl (No Chromium)
Colorless - Goshenite
Aquamarine Yellow - Yellow Beryl
Golden - Heliodor
Pink - Morganite
Red - Red Beryl
Deep blue (fading) - Maxixe Beryl
Chatoyant - Cat's eye beryl
Asteriated - Star beryl
Trapiche emerald - green with black spokes intersecting.
Crystal System / Forms:
Hexagonal System / Generally as six-sided prisms with pyramidal and / or pinacoidal terminations. As such columnar prismatic habits are common.
2.68 - 2.80
Cleavage / Fracture:
Poor cleavage / parting parallel to the basal plane.
; Uniaxial Negative.
Refractive Index / Birefringence:
1.577 - 1.583 / 0.006 - 0.009.
Range: 1.57 - 1.60
Distinct dichroism depending on depth of color.
Parallel two phase or rain inclusions, three phase and crystalline inclusions, fingerprints, hexagonal growth zoning.
Fading blue maxixe beryl: bands at 695
nm & 655 nm with weaker bands at 628 nm, 615 nm, 581 nm and 550 nm. Green and yellow beryl, pink beryl: spectrum is not well pronounced.
Simulants (with separation tests):
fluorescence, doubling), glass (optic character),
Granitic rocks - pegmatite and schists, in hydrothermal veins and metamorphic limestone.
(California, Utah), India (Orissa), Pakistan.
Cuts & Uses:
Facetted cuts, cabochons, beads, carvings, etc.