What to Look For When Buying an Emerald
Colour: The most important quality factor in the May birthstone is colour. Emeralds that are bluish green to green, with strong to vivid colours are highly prized. Emeralds that are transparent are especially valuable.
Clarity: Emeralds typically contain inclusions that are visible to the naked eye, because of this, jewellers understand and accept the presence of inclusions in emeralds. Eye clean emeralds are especially valuable because they’re so rare.
Emerald inclusions are often described as looking mossy or garden like. They’re sometimes called jardin, which is French for “garden.”
In coloured stones, transparency and clarity are closely linked. This is especially true for emeralds. Jewellery professionals generally accept some eye visible inclusions in higher quality emeralds. But when the quantity or nature of the inclusions has a negative effect on transparency and clarity, they also dramatically reduce value.
Cut: Emerald crystals are difficult to cut. Almost all rough emeralds have significant fractures, (sometimes called fissures), and a gem cutter must work to minimise the effect of those fractures on the appearance of the finished stone.
These fissures make emeralds more brittle than other gems. Therefore are vulnerable to damage during cutting, polishing and setting or even from careless daily wear.
The famous rectangular “emerald cut,” with its beveled corners and step cut facets, maximises the shape and weight of the original emerald crystal. It also helps protect against damage because the vulnerable corners are faceted and provide a safe place for claws.
Carat Weight: Emeralds come in a wide range of sizes. There are emeralds in museums and private collections that weigh hundreds of carats. At the other extreme are tiny emeralds that weigh fractions of a carat.