HomeMajor Colored StonesEmeraldEmeralds from Sandawana, Zimbabwe
  • Zimbabwe- Sandawana Valley (S.G.=2.755; R.I.E=1.586, R.I.O=1.593)
    • Mostly small stones (0.5 ct or smaller), heavily flawed in larger sizes
    • Excellent color
    • In schists invaded by pegmatites and quartz veins
    • Noted for inclusions of acicular tremolite, and for somewhat higher R.I. than Colombian and Brazilian emeralds.

You’ve heard of Plato, the ancient Greek philosopher who taught that everything in the material world is a more or less imperfect copy of its original, ideal form stowed in eternity? Well, let’s suppose he had sold gems on the side. And let’s suppose he’d received a parcel of top-grade emeralds from the Sandawana mine in Zimbabwe. How close to the ideal, or archetype, would he have thought these stones?

As close to perfection as emerald gets. That’s why Sandawana emerald, discovered in 1956, quickly reached cult status among dealers and has never wanted since for fervent admirers.

Those fortunate enough to have sold these southern African emeralds talk about the finest of them with the rapture and reverence reserved fro Kashmir sapphires and Burmese rubies. Just listen to this emerald specialist: “The finest emerald I’ve ever seen was a 3-carat Sandawana stone shown me in 1980. It’s owner, an Indian dealer, wanted a mind-boggling $60,000 per carat. But eventually he got it.”

Granted, 3-carat stones of that caliber from Sandawana are extremely rare—so rare that it is possible many precious stone dealers have spent their entire careers without seeing a large Sandawana stone like it. On the other hand, seeing stones of comparable beauty in small sizes was a common occurrence during the two decades when this mine flourished. In fact, Sandawana challenged every aesthetic notion about emerald by proving this beryl could boast a depth and richness of color thought possible only in larger sizes (the result of ultra-high concentrations of the greening agent, chromium). What’s more, stones were remarkably clean, crystalline and fracture-free—the latter virtue so pronounced that oiling, a common touch-up process for emerald, was usually unnecessary.

No wonder dealers who sold Sandawana stones during their brief heyday in the 1960s and 1970s long for their return to these shores.

A DREAM FOR ONE

The first love affair began shortly after Rio Tinto bought the Sandawana mine in 1958. Seven years later, when it decided to switch to a distribution system based on the De Beers single-channel market model for diamonds, it put sales of rough and cut stones in the hands of French gem dealer Jean Rosenthal. He assigned five dealers, himself included, exclusive franchises in France, Germany, Switzerland and the Americas.

For New York dealer Maurice Shire, who oversaw sales in the U.S. from 1965 until 1983, it was a business arrangement as close to ideal as the product itself. Once every 10 to 12 weeks for over 18 years, Shire flew to Paris where he bought the equivalent of a “sight” in Sandawana goods, the most desirable small emeralds in history. While these offerings cost him, on average, $300,00 to $400,000, “they were,” he says, “worth every penny.”

But no matter which locality your emeralds come from, it is very likely they have been given a facial to hide the tiny fissures that are a price these beryls often pay for their beauty. Emeralds, among the rarest of gems, are almost always found with birthmarks, known as inclusions. To eliminate or reduce the visibility of tiny surface breaks requires the gemological equivalent of skin care. For centuries, dealers have been using oils or resins for emerald facials: replace the air with oil and the fissure is much less visible. You should assume that your emerald has been improved in this way unless it has a laboratory certificate indicating otherwise: such rare stones command a considerable premium.

Needless to say, face lifts don’t always last forever. Depending on the substance used, a stone may need re-beautification every once in a while much in the way a car needs periodic oil changes. But while a car needs quarts of oil, an emerald needs an infinitesimally small amount of an enhancement agent to look good—so small it’s usually not measurable by weight. That’s because fissures are usually hair-thin and permit very little material inside. Gemologists can detect the presence of these substances when a stone is examined under a microscope. But it’s nearly impossible to identify the agent without the aid of very expensive equipment that only a handful of labs in the world can afford. For this reason, most gem labs note that an emerald has been enhanced, but can’t say with what medium.

Nevertheless, the trade generally divides enhancement agents into two categories: natural and man-made. Understandably, many dealers dislike the idea of using a man-made substance to beautify a natural gem. Since emeralds have such a long and rich tradition of connoisseurship, these dealers feel that only traditional substances should be used: natural oils and resins such as Canada balsam or cedarwood oil. However, these natural oils, over time, dehydrate or leak out. That’s why most in the trade now rely on longer-lasting man-made substances like epoxy resins for emerald face lifts. No matter which substance is used, the end result is the same: less obvious inclusions, and more life in your emerald.

Knowing this fact of life helps you and anyone to whom you entrust your emerald to protect its beauty. Suppose you take in your emerald jewelry for repair or resizing. The heat from a torch can damage the emerald by forcing a camouflaged fissure to widen. Damage can be avoided by removing the emerald before working on its mounting. Similarly, emeralds can lose their looks in an ultrasonic cleaner, which may remove the filler.

But whether or not an emerald has been enhanced, certain basic rules of gemstone courtesy should be observed. Emerald will not withstand hard blows or other kinds of abuse. So never take your emeralds for granted. Their beauty will be appreciated for generations to come—but only if you treat them with the tender loving care they deserve.

Who are we?

The Geohavens name is an assurance of timeless beauty, distinct quality and uncompromising value. The Company spares no effort in sourcing from the farthest markets and the deepest mines in order to unearth the most attractive gems.

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