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The Best and Most Comprehensive Guide to Sapphires in Los Angeles and on the Web!
Copyright © 2006 INTA GEMS, Inc. All rights reserved.
Enhancements
Nearly every single sapphire (corundum) on the open market today has been heat-treated. It is a very common practice which has been employed for centuries to bring out the purest of the sapphire's hues. The controlled heating of a gemstone is considered a finishing process to complete what nature has started, and is a widely accepted and expected practice by the jewelry industry, the American Gem Trade Association (AGTA), and all major reputable gemstone retailers.
The effects of heating are as permanent as the gemstones themselves because it is merely a continuation of the gemstone's formation process deep in the earth. Fine quality unheated gemstones (which should be accompanied by a certification from an independent third-party laboratory stating that the gemstone exhibits no indication of heating) are rare and generally command much higher prices. Nonetheless, fine quality heated sapphires do still command top dollars and are considered good investments.
Diffusion is another enhancement process in which beryllium or similar element is diffused into the surface of the gemstone, significantly altering the original color of the stone. Diffused sapphires are less valuable and more readily available than untreated or heated stones. Diffusion is also a chemically artificial process and re-polishing or re-cutting the stone might affect its overall color and beauty. If you are purchasing a sapphire for both its beauty and investment value, we do not recommend diffused specimens. Because of the non-permanent nature of the process, diffused sapphires will fade in color over time and thus should be priced significantly lower than heated or unheated sapphires.
Properties such as the uniformity of color, the brilliance of reflected light, and overall clarity are significant factors in determining the quality and the price of sapphires. Properties such as the shape, the style of cutting, and place of origin are all subjective standards and should not be taken as an objective grading requirement in the purchase of a sapphire.
The prices of blue sapphires vary greatly depending on their color hue, tone, saturation, clarity, carat weight, and quality of cut. The prices of loose sapphires are almost always a product of the quality of the stone and its carat weight. The finer the quality or the larger the size of the stone, the higher the total price.
Smaller sized light blue sapphires can cost as little as a few hundred dollars per carat. But a one-carat extra fine blue sapphire can cost $2000 per carat or more. Because all gemstones have a unique combination of color, clarity, size, and cut, the price range for even similar sized stones can vary substantially.