Emerald derives its beautiful green colour from the presence of chromium and vanadium. Emeralds are rarely flawless, so stones are often oiled to fill and disguise kracks, hide flaws, and enhance colour. To minimize the loss of material, the step-cut (or “emerald-cut”, as it is known) is commonly used, but ancient engravings are known, and cameos, intaglios, and beads can make the best of a flawed stone.
Found in granites, pegmatites, and schists, as well as alluvial deposits, the finest emeralds are from Colombia. Other sources are Austria, India, Australia, Brazil, South Africa, Egypt, the USA, Norway, Pakistan and Zimbabwe.
Most emeralds used in historical jewellery would have been from Cleopatra’s mines in Egypt, which now yield only poor-quality emeralds.

Properties

Chemical Composition: Beryllium Aluminium Silicate (Be3Al2(SiO3)6; Trace elements are Cr, V, Fe, Mn, etc.
Classification / Type:-
Colors / Varieties: Green (Cr/V/Fe)
Trapiche emerald - green with black spokes intersecting.
Crystal System / Forms: Hexagonal System
Hardness: 7.5 - 8
Specific Gravity: 2.68 - 2.80
Cleavage / Fracture: Poor cleavage / parting parallel to the basal plane. Emerald is a brittle stone.
Optic Character: Anisotropic, D.R.; Uniaxial Negative.
Lustre: Vitreous.
Refractive Index / Birefringence: 1.577 - 1.583 / 0.006 - 0.009. R.I. Range: 1.57 - 1.60
Pleochroism: Distinct dichroism depending on depth of color.
Dispersion: 0.014
Magnification:
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