natural-emerald

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Colombian emeralds are enjoying an all-time high, and this trend to continue in 2014.

The emerald world as we know it today is primarily dependent on the production of gemstones from three sources: Brazil, Colombia and Zambia. Until very recently each country played a fairly static role in terms of market preference. Colombian emeralds dominated the high end, Zambian gems occupied the middle, and Brazilian stones were considered to be more commercial. While this positioning is still pretty much intact, there are always exceptions and some Zambian and Brazilian stones may rival even the best stones from Colombia.

Most emeralds are already included and fractured throughout and dealers  and cutters select the best and cleanest stones for faceting. There are  of course differences between individual stones, but there is no  important mining area that produces emeralds more stable or less included than stones from other deposits. This means that visible inclusions in emeralds are common and expected and emeralds are judged with a greater emphasis on color and transparency and included stones are accepted. While emeralds without eye-visible inclusions do exist, these stones are extraordinarily rare. Some inclusions in emerald are referred to as jardin, (meaning garden in both French and Spanish) and may consist of networks of tiny liquid filled inclusions and minute fissures that permeate the gem evoking the appearance of a lush garden. These inclusions also impart the emerald with a distinctive sometimes hazy appearance because they diffuse and spread light through the gemstone.

vine

Emerald Bay, Lake Tahoe

It’s a last Emerald #ColoroftheYear Monday

Colombian emeralds will typically be the most expensive followed by Brazilian and Zambian stones. The reasoning is related to the color. Colombian emeralds get their color primarily from the trace amounts of the element chromium which is responsible for some of the purest greens in gemstones. Brazilian emeralds get their color primarily from trace amounts of the element vanadium and Zambian emeralds get their color from iron. Brazilian emeralds typically have a slight brown or gray cast and only sometimes match the pure green hue that many Colombian emeralds offer and Zambian emeralds often appear too blue due to their iron content. In reality though, emeralds from all three sources may be colored by more than one element.

Gem Science: Synthetic Gems

Some Gems can only be created through synthetic means. Either they don’t occur in nature in the desired quantities, or their natural look isn’t acceptable for high fashion. Most synthetic Gems are created for scientific observations or as a by-product of heavier elemental fusion, but the ones listed below are some of the ones available commercially.

Artificial Gems

Gilson Gems

A French company named Gilson has pioneered almost all of our modern synthetic Gem creation techniques, and they have allowed many people to purchase Gems that normally would have been far too rare to afford. Below is a polished bead of Gilson Lapis Lazuli, virtually indistinguishable from the genuine article.

The Gilson technique also creates most of the world’s Turquoise and Coral, both extremely rare and difficult to harvest Gems. However, Gilson Emerald has flaws that make it worthless in high-class jewelry due to the difficult-to-replicate nature of Emerald. 

Flux-Melt 

The only way to generate synthetic Emerald is through the Flux Melt technique, which was pioneered Edmond Fremy. By mixing a solvent with the secret patented ingredients and heating them for months, a synthetic Emerald is formed. However, like Gilson Emeralds, these Gems are of poor quality and do not measure up when examined with a loupe.

Flame-Fusion

To create synthetic Corundum (Rubies, Sapphires) a different technique called Flame-Fusion must be used. Again, secret patented ingredients are run through a 4,000 F flame that causing them to fuse together in liquid form. This liquid then slowly drips onto a platform, creating a large stalactite of Corundum known as a boule. This boule can be shaped in the desired cut and the rest is re-melted to be made into more Gems. By altering the ingredients, Rubies and Sapphires can be formed.

Imitation Gems

Glass

Glass Gems have been used as a cheap stand-in for centuries, but these can be easily broken or become dull over time. On the plus side, glass can be used to create any transparent Gem, and is sometimes featured in collections as a Gem itself due to it’s unique refractive properties.

Imitation Opal

Once again, Gilson shows up with their signature product, Gilson Opal. Opal is a Gem that is flexible with how it’s created and set, meaning that some Opals, like most Opal Doublets, are a combination of synthetic Latex Opal and natural Opal. However, synthetic Opal’s play of color resembles a mosaic while natural Opal is a much subtler, pastel gradient. An Opal Triplet is a natural Opal base layered with a synthetic Opal on top, then final covered in a Quartz finish.

Imitation Diamond

Perhaps one of the most common offenders, imitation Diamond is very often seen in pop culture. Cubic Zirconia is by far the most common, but the main giveaway is that Zirconia is much heavier than Diamond. Strontium Titanate is also a popular choice, but it is much softer than Diamond can has a deeper brilliance. Finally, Yttrium Aluminum Garnet, or YAG, is a rarer but still viable imitator, but is unpopular because it looks duller than both the others and is much, much heavier.

Doublets and Triplets

Sometimes you can combine a rare Gem with it’s imitator to produce a passable fusion, called a doublet or a triplet. A doublet is made up of a backing of the actual Gem, covered with a large cut of the imitator. This way, the reflection of the actual Gem can be seen through the imitator, and the cost is kept down. A triple is the same but covered with a coating of Quartz or Glass.

Color Correction

Staining

This technique can only be used on porous Gems, such as Lapis Lazuli or Turquoise. By applying a reactive chemical or paint to the Gem, you can radically enhance its natural color or cause it to look like another. Howlite, when stained blue, becomes imitation Turquoise. In particular, Jet and Lapis Lazuli are stained to bring out their deep blacks and blues.

Irradiation

By exposing a Gem to radiation, you can deepen its color. However, Gems are energy conductive, so sometimes the Gem will slowly return to its normal color as it release the radioactive energy over time. Amethysts and Topaz are very famous for the rich purples and blues they take on when exposed to radiation.

Oiling

The use of oils to subtly change a Gems color is an ancient practice, but these days oiling is used to head cracks or blemished, particularly in certain species of Emerald.

Heat Treatment

Extreme heat can cause a Gem to change color. By throwing Brown Zircon in a fire for an hour, you’ll get beautiful Blue Zircon. Sometimes, the color change is unpredictable and you’ll end up with uneven colors or rainbow gradients.