The Hooker Emerald Brooch, 75 carats and located in the US National Museum of Natural History
Probably a lot of people know that the birthstone of May is the emerald. It is a beautiful green stone that can make any jewelry sparkle. The emerald is a variety of the mineral beryl and is green because of the trace amounts of chromium and sometimes vanadium found within the gemstone. It is rated 7.5-8 on a 10 point Mohr scale and can be heavily included which contributes to its toughness, which isn’t so hot. Regardless, emeralds are beautiful gemstones and their deep green color is rarely surpassed. Those of you lucky enough to be born in May should take the opportunity to stock up on some emerald jewelry.
When I investigated emerald there was a long and convoluted way in which the name was derived. Emerald comes from Esmeraude (French) which comes from Esmaralda (Vulgar Latin), which is a variant of Smaragdus, which comes from smaragdos which means green gem in Greek but was originally izmargad meaning emerald or green, from Hebrew. Are you thoroughly confused, I am. When I read further on they added several other words that it could have been derived from including words from Sanskrit and Persian. The fact that the name emerald is derived from so many possible origins is interesting and the Sanskrit and Persian references give it an exotic flavor. Kind of cool.
What is interesting about emeralds is they have similar standards for grading as diamonds, such as, cut, color and clarity but the clarity is defined with the naked eye, not with a loupe. Emeralds are notorious for inclusions and surface fissures so grading with a loupe would cause few emeralds to be graded as flawless. The human eye cannot see inclusions as well without the aid of a loupe. I guess grading emeralds without a loupe is kind of giving the emerald a break. Due to surface fissures many emeralds are oil treated to enhance clarity. This is an accepted practice so there is no need to freak out. Although it is important to remember that while cedar oil is accepted, green colored oil is not, it’s kind of like cheating.
Just like any gemstone you purchase, they can look the same but can vary greatly in treatments. Emeralds that are highly treated are worth far less than emeralds that have had little or no treatments. This is why it is important to talk to the retailer when purchasing an emerald, or for that matter, any gemstone. Treatments are common in the gemstone industry and many treatments enhance the look of the stone, but remember, not all treatments are created equal. You want to find a piece of jewelry that not only looks good, but is a fair value for the money. One of the ways to ensure this is to ask questions, because it never hurts to ask, it only hurts when you didn't ask.