Tuesday, May 4, 2010

Treated and Untreated Diamonds

Reprint from my article on Suite101.com "Enhanced Clarity or Treated Diamonds: A Diamond Alternative"

Treated diamonds are not a new thing. For many years diamonds have been enhanced by fracture filling, drilling, and painting. Clarity enhanced diamonds fall into two categories, permanent and not permanent treatment. It is worth noting that the treated stone is a cheaper alternative to a similar looking, more expensive, untreated diamond.

What Diamonds are Treated

Diamonds which are clarity enhanced, by fracture filling, usually fall into the commercial or the I1 to I3 clarity range. However, even VS clarity diamonds may be treated with laser drilling. Color treatment can be done on all diamonds and the buyer should refer to a diamond certificate. According to Willam George Shuster in his article "What Store Managers Must Know About Fracture Filled Diamonds" published Feb. 1, 1998 in JCKonline, majority of clarity enhanced diamonds on the market are in the .50 to 1 carat in size. However, smaller diamonds are routinely treated as well; they can often be found in tennis bracelets.
When selling a diamond, the seller is obligated by law to disclose all treatments. He must tell make it known to the buyer that the stone is treated and if the treatment is permanent or not. This does not guaranty that the buyer will be informed as there will always be dishonest people, but the law is on the consumer’s side.

The Clarity Enhanced Diamond

A clarity enhanced diamond has been ether fracture filled or laser drilled. GIA and many other laboratories will not grade a fracture filled diamond because the treatment is not permanent and so the certificate will possibly not match the stone in some time. They will however grade a laser drilled diamond as the treatment is permanent.
Fracture filling a diamond is a process by which the cracks or fractures in a diamond are coated or filled with a glass like substance. The treatment enhances the appearance but not durability, and can make an I2 clarity stone look like an SI2 clarity diamond. The treatment can be reversed by exposing the diamond to high temperature. It can also be damaged by heat, ultraviolet light and ultrasonic cleaning. If the stone is brought in for cleaning to a jewelry shop, though the treatment is detectable, the customer should always disclose to the jeweler that the diamond is treated.

Laser drilling is done by burning out of dark inclusions in a diamond. This can be done in any clarity graded diamonds. The process is permanent and easily detectable. After the treatment, white tunnels are left where the inclusion used to be. Lighter inclusions are considered better then dark ones, which is why this treatment is performed.

It is recommended by Mr. Shuster that the value of a diamond should be based on its original price plus the cost of the treatment. The buyer will not pay the same for an I2 treated diamonds the same as for an SI2. This makes a clarity enhanced diamond a great alternative to a more expensive stone, considering that only the buyer will know of its true clarity grade.

Color Enhancements

Color treatments can range from primitive to very sophisticated. Many years ago, people used to paint the girdle, or side of the stone, with blue ink to counteract the yellowish tint of the stone. This made it appear white. Later, a thin film was applied to the whole stone which produced a similar effect. Today, diamonds are treated with HPHT high pressure high temperature treatment to make some yellowish diamonds to look white by changing their crystal structure. HPHT treatment is permanent and usually disclosed. The others are not permanent and are rarely used by the trade, and are only applied to trick someone.
In conclusion, the clarity enhanced diamond is a good alternative to a more expensive diamond. It is worth noting that some treatments are permanent while others require more attention and careful handling. To read about other alternatives to diamonds read Diamond Alternatives for Engagement Rings.

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