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What Are Irradiated and HPHT Color Treated Diamonds

What You Need to Know When Shopping for an Engagement Ring


A Colorful Trend

Very recently the colored diamond has come into vogue, appealing particularly to those who crave distinctive jewelry that expresses their individuality. Brown diamonds, which occur naturally and are not as rare as more vivid hues such as blues, greens, yellows, and pinks, have gained popularity and have become known by such tempting terms as “chocolate” or “champagne.” These deliciously named brown diamonds are not treated in any way, and occur relatively often in the realm of diamonds. In contrast, diamonds that are naturally vivid in color - such as blues, greens, pinks, and yellows - are extremely rare, and often prohibitively costly. Naturally occurring colored diamonds can be found organically in every shade of the spectrum, and each and every stone is unique unto itself. The physical conditions required to form these miraculous anomalies of nature occur so rarely that only one diamond in 10,000 possesses a strong natural color; these intensely colored diamonds are known as “fancy” colored diamonds. For example, blue diamonds great and small are priced according to rarity, and it is not uncommon to find stones under .25 carats with five-digit prices. The same principle is true for diamonds of colors other than blue, especially the very rare pink diamond. Paler pinks with secondary hues are more common than pure and intense pinks. Natural fancy pinks are appreciably rare, regardless of secondary colors and are priced accordingly. Fancy diamonds are valued using different criteria than those used for regular diamonds. When the color is rare, the more intensely colored a diamond is, the more valuable it becomes. Fashion trends and celebrity whims can also have an effect upon the value of a particular color of stone. For instance, when Jennifer Lopez received an engagement ring with a pink diamond in 2002, the pink diamond became highly coveted, and has stayed that way. In 2010, a 24.78-carat fancy intense pink diamond sold for an astonishing $46 million - close to $2 million per carat. More recently, a 2013 article names colored diamonds as one of its “top four hottest trends in engagement rings right now.”


More Affordable, but Equally Impressive

Fortunately for the fashion-conscious shopper who wants unique, statement-making jewelry for a reasonable price, there is a beautiful alternative: a diamond whose color has been changed by irradiation or by a process known as High Pressure High Temperature treatment. Irradiation achieves vivid yellow, blue, green, and black colors, while HPHT typically results in yellow or purple-pink hues. Irradiated yellow diamonds usually come in orange-yellow and darker shades of yellow color, whereas HPHT processed yellow diamonds tend to be bright yellow. The irradiation process alters the stone’s internal molecular arrangement, thereby changing its optical properties/color. The High Pressure High Temperature process can achieve bright yellow colors and purple-pink hues. Though not a requirement, the heat-treated or irradiated colored diamonds used in Jewelry Point’s jewelry are only naturally occurring diamonds, and have not been treated to enhance their clarity. Only a small number of diamonds will yield the very popular purple-pink color when they’re treated, so this color of diamonds is more expensive compared to some of the other colors. Also, only the cleanest diamonds can be made in purple-pink, as high pressure can destroy the stones if there are inclusions. Besides cost, another advantage of irradiated diamonds is the fact that the color of these heat and radiation-treated diamonds is consistent throughout the stone; the brilliant hue you see isn't skin deep, or a mere coating, and it will never fade.


How It All Started

Although colored diamonds are a 21st-century fashion statement, the process of irradiating diamonds to change their color has been known since the early 20th century. In 1904, British scientist Sir William Crookes set out to prove that diamonds could be tinted in this manner by burying small diamonds in radium bromide salts. Unfortunately, this method took months, produced only a “skin-deep” green color, and rendered the stones radioactive. In 1942, diamonds were greened more than superficially over days in a Michigan cyclotron without becoming radioactive for more than a few hours afterward, and the stage was set to color diamonds in a safe, fast, permanent way. The next step was for gemologists to find out how to create a wider palette of colors. By coupling irradiation and heating, research gemologists began producing green, blue, yellow, brown, and black diamonds on a commercial scale in the early 1950s. In the 21st century, in response to consumer demand for unique and very personalized jewelry, colored diamonds have become highly fashionable and extremely sought after, particularly for engagement rings.


Health Concerns

Modern shoppers need not be concerned about the possibility of health hazards associated with the radiation that changes diamonds’ colors. According to, which is the United States Nuclear Regulatory Commission’s website: “Any dose [of radiation] from these gems would be extremely small. The NRC did a study to estimate the dose to a person wearing a large blue topaz stone (six carats). Assuming the stone had the highest level of radioactivity allowed under NRC regulations, the dose during the first year could be 0.03 millirem (NUREG 1717, page 2-21). Having a porcelain crown or false teeth would give twice that dose (0.07 millirem), while a chest X-ray gives about 60 millirem. But this estimate is conservative. The radiation continues to decay, so the dose rate would go down over the course of the year.”


An Array of Options

Irradiated diamonds are not the only possible choice for those jewelry buyers who want something new and different, either. The brown diamonds sold by Jewelry Point are natural and untreated. Additionally, Jewelry Point offers 100% natural untreated Gemological Institute of America-certified yellow and pink diamonds; customers who are interested in these types of yellow and pink diamonds should contact us to inquire about availability and prices.
In 2014, even the most fashion-conscious jewelry shoppers enjoy a variety of options when it comes to selecting unique pieces that express the giver’s and wearer’s personalities and tastes, without causing financial strain or compromising style or quality. Depend on Jewelry Point for colorful, stylish, high quality jewelry that makes an eloquent and lasting impression.




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