Emerald is a member of the Beryl mineral family, and is composed of beryllium aluminium silicate. For those who love chemistry, its formula is (Be3Al2(SiO3)6 For the crystals to develop, beryllium must be heated to over 750 degrees Fahrenheit and put under up to 21.75 tons of pressure per square inch. As pure beryl is colorless, there must also be trace amounts of chromium and / or vanadium present during the crystal formation to give the gorgeous green color. Some of the oldest emerald mines in the world, nicknamed “Cleopatra’s Mines”, are located near the Red Sea in Egypt, and may have been worked as early as 500 B.C.E. Egypt was the major source of these gems until better quality stones in larger quantities were discovered in the 1520’s in an area of the “New World” in present day Colombia. Now, emeralds are mined throughout the world but the three main sources are still Colombia, the largest producer, followed by Zambia, then Brazil, where the enormous 752lb or 321kg rough Bahia Emerald specimen was mined in 2001.
On the Moh’s hardness scale, an emerald would rank around 7.5 – 8, but they usually have many inclusions, (impurities), which render them brittle and susceptible to cracking. The famous rectangular “emerald cut” for gemstones was developed specifically to reduce the amount of pressure put on an emerald during cutting whilst giving a beautiful stone ready to set in jewelry. The prevalence of inclusions is also the reason that emeralds should be cleaned gently and NEVER put in an ultra-sound jewelry cleaner! Instead, immerse the emerald jewelry in lukewarm water containing a mild soap and use a soft toothbrush to clean around the stone, then rinse it thoroughly and dry with a clean micro-fiber cloth.
Carat for carat, a large untreated emerald with minimal inclusions, deep color and excellent clarity is hard to find and would be worth more than the equivalent size and quality of diamond. For this reason many treatments, such as oiling or the addition of polymers such as Opticon, have been developed to enhance lower quality emeralds, and imitation and synthetic lab-produced emeralds abound. When buying an emerald, it is a case of buyer be aware. If the emerald is large and of high value, it is best to have the stone independently certified to verify authenticity by a professional gemologist from a recognized institute, not by the seller of the gem.
I am a May baby, so emerald is my birthstone, and I found it fascinating reading the history and lore associated with these beautiful stones. However, whatever your birth month, there are many reasons to GO GREEN!
~ Lin Chapman ~
Flaunt Designs Jewelry