Sapphire Gems for Sale
Sapphires are one of the most popular of all colored gemstone types. Like all precious gems, they are rare and expensive. Natural sapphires are offered for sale at prices exceeding several thousand dollars per carat. Very fine specimens can cost considerably more.
Yet, sapphires are also sometimes offered at much lower prices, sometimes for as little as $30 or $50 per carat. What is the reason for this vast range in price?
The first thing to look for in sapphires for sale is whether they are natural or synthetic. Though synthetic sapphires are chemically the same as natural sapphire (corundum or aluminum oxide), synthetic sapphires are mass produced in laboratories at low cost using a method known as flame fusion. Generally, reputable gem dealers do not sell synthetic sapphires. Such gems are used mainly in low cost commercial jewelry. Whatever the use, they should always be disclosed as synthetic.
Low cost natural sapphire tends to be mostly treated or lower quality material. Lower grade material is typically of inferior color or clarity. Some of the lower grade material of poor transparency is cut as cabochons rather than faceted. If the color is good, these can be very attractive, but they will sell for much lower prices than facet-grade stones.
Sapphires of inferior color can sometimes be improved by treating the stone with various methods. A relatively new method that is used on off-color stones is known as beryllium heat treatment or lattice diffusion. It involves heating sapphire with the light element beryllium, which dramatically changes the color of the gem. Most beryllium-treated sapphires are a vivid yellow, orange or orange-red. As this treatment is becoming increasingly common and accepted in the trade, prices of these diffused stones are rising.
The most common treatment method for sapphire is heat treatment, which involves high-temperature heating that affects impurities in the sapphire, such as titanium or iron. The end result is often an improvement in both the color and clarity of the gem. Heat-treated sapphires with top color and clarity can be quite expensive, especially in large sizes.
The rarest and most expensive sapphires are completely untreated. Sometimes they may be found at affordable prices in small sizes (under 1 carat), but unheated sapphires over 1 carat will generally be expensive. Large stones (over 2 carats) with very good color can easily sell for $1000 per carat and often more.
- Primera publicación: Diciembre-25-2009
- Última actualización: Septiembre-29-2017
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