Most people are familiar with clear, faceted emeralds like E1071. The rough, uncut form of emeralds are virtually unknown to most, and even fewer know that there are different grades of emeralds and other than the faceted gems.
There are 3 main grades of emerald rough. For gem cutters and other discerning individuals (lab gemologists, specimen collectors, geologists, etc), there are more categories and grades that are beyond the scope of this article. The main grades are broken down into carving grade, cabochon grade, and facet grade. As mentioned above, E1071 is an example of facet-grade emeralds.
E1071 | play | medium | “Emerald ID: E1071 – Weight: 1.24 Carats – Origin: Zambia”
Carving grade emeralds are the most common, and considered to be the lowest grade. They are typically opaque to semi-translucent, and as the name suggests, usually carved.
A very famous example of this is the Moghul Emerald. The front is naskh script, an early type of Islamic calligraphy and the back is a carved floral pattern. This carved emerald is also one of the most expensive emeralds in the world with a value of over $2 million USD. A big part of that price is the historic importance and the quality of the carving, along with an authentic date on it around 1695 AD.
Cabochon grade emeralds are the second highest quality emeralds, with the name derived from their shape. Cabochons are always partially rounded, with their shape ranging from circular to pear. Their bases can either be flat or curved, but one side is always cut as a dome. The clarity of this type of gem material ranges from opaque to semi-transparent.
A large reason for the selection of emeralds for certain shapes is a concern of durability. The more internal fractures the uncut gem has, the more likely the gem cutter will shatter the gem while polishing it. This is also why experienced gem cutters are so desirable in the gem trade.
E1591 | play | medium | “Emerald ID: E1591 – Weight: 5.20 Carats – Origin: Zambia”
E1027 | play | medium | “Emerald ID: E1027 – Weight: 1.41 Carats – Origin: Zambia”
Clear, transparent emeralds are the cream of the crop in terms of gem quality. Not only are they pretty, but they’re also durable. The faceting process for emeralds, and most gems in general, is a brutal process that can shatter the gem a cutter is working on if they are not careful.
The emerald cut as shown left was specifically developed for emeralds due to durability issues caused by their inclusions. Modern cutting techniques have significantly reduced the impact on these gems, allowing them to be faceted in almost any imaginable shape from round to pear, as well as shine brighter overall.
Currently the emerald cut is reserved for specific gems that show impeccable clarity, much like the example E1027.