Apparently, apart from being girls’ best friends diamonds are also known as the priciest gems in the world. But there is the difference between them primarily in size, cut, clarity and color. While the first three affect the price, this is the last one that skyrockets it to sometimes unbelievable costs. Now it’s clear why diamond jewelry manufactures resort to all possible ways that can help them intensify the color of a gem.
If you are a diamond expert, you won’t have problems in distinguishing a real colored, not-treated diamond from a gem that underwent certain coloring. But if you are a common customer looking for a fancy colored diamond and don’t want to be cheated by the retailers, this article can be rather handy for you revealing some basic secrets of how diamonds can get their color. But one the other hand, there are some methods of diamond treatment that are permanent and used to enhance the color of a gem. In this case it’s better to get more information about diamond treatment and stick to the golden rule ‘Forewarned is forearmed’. So, the methods are as follows:
Coatings & Other Color Tricks
Coatings applied to change a diamond’s color are not permanent and are nearly always done to deceive the buyer.
Diamonds are sometimes coated with a substance that masks yellowish tints. Though it is applied with heat, the coating will eventually rub off with normal wear and cleaning.
Sometimes dots or larger areas of purple or blue ink are painted on the diamond to help counteract a yellowish color. The dots are usually obscured by the diamond’s setting, so they are difficult to see in a mounted stone. The coating can usually be removed with water or cleaning solutions.
Creating Colorful Diamonds
Irradiation, followed by a high heat treatment, can turn brown and yellow diamonds into fancy colored diamonds–greens, vivid yellows, blues, purples, reds and other colors. The color is usually permanent, but could possibly change if high heat is used during setting repairs.
Natural fancy colored diamonds are expensive and out of the reach of most buyers. A certificate from a respected grading lab should accompany all fancy colored diamonds that are marketed as natural.
Question the ethics of anyone who attempts to sell you a natural fancy colored diamond for a bargain price.
Treatment-produced fancy colors are affordable, and allow more of us to own a brightly colored diamond. They should not be considered an investment. Buy one because you love it, not because you think you can sell it for a profit later.
Ask the jeweler for care instructions when you buy an irradiated fancy color diamond.
High Pressure High Temperature Treatment (HPHT)
HPHT was first used to turn yellowish diamonds into fancy colored diamonds, but now it is also used to transform some unpopular brownish diamonds into more expensive colorless diamonds.
Some companies claim HPHT isn’t a treatment at all, calling it a technique that finishes the job nature started. That attitude, and the fact that the process is difficult to detect, has made HPHT a controversial topic.
General Electric is producing colorless diamonds, called Bellataire, from type IIa diamonds that are nitrogen-free. The company has applied for a patent on the process used to transform the stones. On their Bellataire Web site, GE states:
“BELLATAIRE Diamonds are extremely rare Type IIa diamonds that were originally crystallized without color and were destined to become extraordinary gems. During their journey to the surface of the Earth through volcanic pipes, though, these crystals were subjected to intense heat, tremendous pressure, and explosive turbulence. These conditions caused some molecular misalignment in these crystals, resulting in a brownish color and internal stress.”
GE’s position is that the process they use restores diamonds to their colorless state.
Gemological Institute of America (GIA) grading reports now indicate when HTPT treatments are detected by stating “HPHT Annealed” or “Artificially Irradiated” in the Origins portion of a report.
Only diamonds that are laser-inscribed with the words “HPHT PROCESSED,” “IRRADIATED,” or a specific registered name are graded.
GE uses a registration number and the letters “GE POL” to inscribe their diamonds.
There have been instances where inscribed lettering has been removed before a diamond was submitted for grading.
HPHT will continue to be a controversial topic, with grading labs trying to perfect ways to detect the always-improving process so that consumers can receive full disclosure about the diamonds they purchase.
Should you purchase an HPHT diamond? You’re the only one who can make that decision. The diamonds are definitely gorgeous, but choosing between altered and natural is a personal decision.
A few facts about HPHT Diamonds:
HPHT is permanent.
The Federal Trade Commission (FTC) requires that HPHT be disclosed.
Most HPHT diamonds weigh over 1/2 carat.
HPHT diamonds should cost less than similar natural diamonds.
This information is taken from http://jewelry.about.com/cs/diamondtreatment1/a/color_treatment.htm