Gem-quality diamonds come in a multitude of colors, including some so rare that the phrase “one in a million” would exaggerate their numbers. Diamonds in the pink color range are not among the rarest of the rare. They’re more common than, say, blue, purple, or red diamonds, but compared to fancy brown, orangey, and yellow diamonds—the most common fancy diamond colors—they’re both rare and pricey. Most jewelry showcases display diamonds that range from colorless to those with a faint tint of yellow or brown (and sometimes gray). Most retail jewelers and consumers have been inundated with advertising urging them to look for diamonds with little or no color—colorless, ice-like diamonds. That’s why most people still don’t realize that diamonds occur in nature in all colors of the rainbow.
But now the ads are changing, and jewelers and consumers are discovering the virtues of fancy colored diamonds. Because of limited supply and high prices, demand for colored diamonds will never approach that of near-colorless or colorless diamonds. But fancy colored diamonds are magnificent gemstones and are sure to capture the imagination of the right customer at the right time.
History and romance. Pink colored diamonds have come from at least four different locales: India, southern Africa, Brazil, and Western Australia, where the Argyle mine is today best known for its incredible wealth of pinks. (See “A [Very Expensive] Pink Diamond Souvenir,” p.32.) The most historically significant pink diamond, the Agra—an Indian stone reportedly dating back to the late 1400s—weighs 28.15 cts. It was graded as a 32.24-ct. Fancy Pink in 1990, prior to its latest recutting.
Qualities. A discussion of diamond quality usually includes all “four Cs”—carat weight, clarity, cut, and color. With pink diamonds, color is the most important “C,” with cut and carat weight probably tied for a distant second place.
Cut can effectively alter a diamond’s inherent body color to give it a different apparent color in the face-up position. Apparent color is most important—that’s what the customer sees. Cut also affects weight. And even though diamond prices are set per carat, weight doesn’t trump color. But because bigger diamonds are more rare and important, carat weight and cut are almost linked in value and importance.
Clarity is the least important factor. Only eye-visible inclusions will detract from a stone’s overall appearance or affect beauty or salability. The color of pink diamonds is associated with pink-colored graining inside the gem. The more colored graining, the more saturated the color. However, this graining affects the clarity grade. So it’s difficult to find an obviously pink diamond that is also internally flawless.
Color variations. Pink can be modified by five other hues—orange, red, purple, brown, and gray. In fact, because of the uniqueness of each modifier, the origin of many pink diamonds can be estimated by the strength and modification of the pink color. For example, most light pink or orangey-pink diamonds come from southern Africa; most Fancy Deep Purplish Pink diamonds come from Australia. And if your first guess is wrong, Brazil is the next best guess.
Color grade ranges (according to the Gemological Institute of America’s Gem Trade Lab) begin with faint pink, a color that’s barely visible through the pavilion of the stone, and not visible face up. Next on the scale are very light pink and light pink stones, which show some color face up. The rest of the grades include the fancy color grades, which show obvious color face up: Fancy Light Pink, Fancy Pink, Fancy Intense Pink, Fancy Vivid Pink, Fancy Deep Pink, and Fancy Dark Pink, all of which may be modified by secondary hues of orange, brown, purple, or gray.
Enhancement. Irradiation is an obvious way to create a pink diamond, but because there are few diamonds that can be changed to pink through treatment, even irradiated pink is a rare color. It also may be possible in the near future to create pink diamonds from light brown diamonds using high-pressure, high-temperature treatments. Experiments with HPHT have already produced a few such stones.
Pricing. For fine-quality pink diamonds, get ready to spend some money. Half-carat Fancy Pinks in VS or SI grades can range from $25,000 to $40,000 per carat, and prices for Fancy Intense stones are even steeper.
Care and cleaning. Like any diamond, pink diamonds can withstand all sorts of wear and tear, ultrasonic cleaning, and steam cleaning. But because of their value, a little extra caution is prudent.
Bench repair and setting. Always clean diamonds before putting a torch near the gem. Diamond can take the heat, but if someone has handled a diamond, be aware that natural skin oils left on the stone can, when heated, burn its surface. Burn marks can be polished away only by a professional diamond cutter.
Recommended reading. For more information, see Collecting and Classifying Coloured Diamonds, by Stephen C. Hofer, Ashland Press, 1998.