Emeralds
Emeralds are a rare green variety of the mineral beryl. The green comes from the chromium content.
Since early times emeralds have been highly valued and, indeed, a high quality emerald can even be worth or valued more than a diamond.
Although generally considered the green gem, emeralds actually come in a variety of other colors depending on the various impurities nature has imparted into the stone. The blue stone is known as aquamarine and the pink shades are known as morganite. You can get yellow and golden emeralds also and, even rarer, red.
Emeralds are quite hard being in the range of seven to eight on the Mohs hardness scale. Just below Rubies nine and diamonds at ten. Emerald is the May birthstone and traditionally given for the 55th wedding anniversary.
Some of the most beautiful emeralds come from Colombia and these are often a brilliant green yet tinged with a blue quality. Emeralds are also found in Afghanistan, India, Pakistan, Russia, South Africa and Zimbabwe.
Most emeralds are treated to enhance their appearance. This includes immersing in oils to fill cracks and prevent further cracks due to the stone drying out excessively. Also epoxy resin and resins are used to fill in cracks and improve transparency which is why cleaning of emeralds should be carefully done and not include ultra-sonic devices as they can remove the oils and coatings.
Two famous emeralds include the Gachala Emerald, which is an uncut emerald crystal weighing 858 carats or 172 grams. This stone was found in 1967 at Vega de San Juan mine in Colombia and is named after the mining district where it was discovered. It was donated to the Smithsonian Institution by the New York jeweler, Harry Winston.
The other one is the Chalk Emerald and this weighed in at37.82-carats. It originally weighed 38.40 carats, but was subsequently recut and set in a ring, where it is surrounded by sixty pear-shaped diamonds totaling 15 carats by Harry Winston Inc. The ring is housed in the National Gem and Mineral Collection at the Smithsonian Natural History Museum and was donated to the museum by Mr. and Mrs. O. Roy Chalk in 1972.
Emeralds are used primarily in jewelery and look wonderful set in rings and necklaces. When looking for a good emerald always ask for a certificate to show its authenticity and value.