Characterization

Emeralds are a variety of the mineral beryl ( Be3Al2(SiO3)6 ) colored green by trace amounts of chromium and sometimes vanadium. Most emeralds are highly included, so their brittleness (resistance to breakage) is classified as generally poor. Emeralds come in many shades of green and bluish green. There is a wide spectrum of clarity, dependent on the inclusions and fractures in the crystal. Clear stones with dark yet vibrant color command the highest prices. Almost all emeralds contain numerous flaws, cracks, and inclusions, which can negatively affect the clarity. These are given the name "jardin", from the French word for garden.

The value of an emerald depends on cut, color, clarity, and carat. The emeralds are weighed in carats (not to be confused with kilates, as it refers to the purity of gold), with carat equaling 1/5 grams. Because of the relatively low consistence of emeralds (SGE = 2, 72), they appear to be bigger than rubies and diamonds and with the same weight.