Rapaport Magazine
Colored Gemstone

A Connoisseur’s Gem

Delicate color and an intriguing history make kunzite appealing to collectors.

By Brooke Showell

When a significant supply of a new purplish pink spodumene was discovered in 1902 in the Pala area of California’s San Diego County, gemologists touted its beauty. Following gemological tradition, George Kunz of Tiffany & Co., as the first person to identify and classify the new
gemstone, named it kunzite after himself.

Kunzite comes in a range of colors, from pale pink and light rosy lilac to a deep amethyst, and owes its color to the presence of manganese. The gemstone is known for its clarity and for its multiple color nuances that can be brought out by expert cutting. There’s also reportedly a spiritual quality to kunzite, which some believe has a calming influence that reduces stress and tension.


Lindsay Wolf
The more saturated, vivid purple-pink generally is considered the most desirable color, but favorite shades often come down to personal preference. Not only is kunzite’s pale pink shade an appealing fashion choice, but this hue also is a more exotic and more affordable choice than its more common counterparts on the color wheel, like pink sapphire or tourmaline. “There’s no other stone that comes like kunzite — large, flawless, clean and inexpensive,” says William Larson, president of Pala International, gemstone dealers in Fallbrook, California.

Retailer Rusty Roth, co-owner of Roth Brothers Jewelers in Monticello, Indiana, used a large natural kunzite stone purchased from Pala that measured approximately 1 inch in length and one-half inch in width to produce a necklace for a customer looking for a special light pink piece. “It’s not a really expensive stone. You can get a large stone that makes a statement without spending near what you would with a pink sapphire,” Roth explains. Kunzite is only fairly durable, rated as a 7 on the Mohs scale, which is one reason, Roth says, “you probably would choose to use it in a necklace because it’s not going to get a lot of abuse like it would in a bracelet or ring.”

The discovery of kunzite in Southern California in 1902 was followed eight years later by a discovery in Brazil. A third supply was discovered in 1970 in Afghanistan.

SOURCING THE STONE

The U.S., Brazil and Afghanistan remain the main suppliers of kunzite today and sources say the differences in stone color among these sources are not immediately obvious. Madagascar was an early source — kunzite was found there even before the discovery in Brazil — but the country hasn’t produced a supply of the stones in about 80 years.

Although mining in Afghanistan has tightened up in the past year and production in the Mawi mines of Afghanistan’s Laghman Province, known to have some of the best kunzite in the country, shut down because of the cost-prohibitive price of the explosives used in mining operations, there are still large stockpiles of stones in the area. While much of this Afghanistan kunzite was once exported as rough to destinations like Hong Kong or Bangkok, a gem-cutting industry has developed recently near the Afghanistan border in Peshawar, Pakistan. Larson estimates this foreign-sourced, irradiated kunzite ranges from about $2 to $10 per carat, while the finer, natural,untreated American kunzite from Pala, California’s Oceanview Mine is priced closer to $40 to $50 per carat. This domestic material is custom cut by more skilled American cutters. Brazil is also known for its expert cutters of kunzite, and much of the Afghanistan material is sent there to be cut.

“We had a couple of pockets, but it’s been lean for more than a year,” says Mark Mauthner, sales manager of Oceanview Mine. Some of the more remarkable finds of California kunzite — single stones of 100 carats to 200 carats in a rich purple color credited to the region — have been bought for the collections of museums and universities, enhancing the stone’s reputation among collectors. Other stones’ origins may be more difficult to classify.

TREATMENT

Kunzite, specifically stones from Afghanistan or Brazil, is often heat treated and/or irradiated to give it a deeper, more intense amethyst-like color to increase its desirability and, in turn, its price tag. “I think a lot of dealers, whether it’s indicated or not, say kunzite has been treated, but they don’t know if it’s been heated or irradiated,” says dealer Dudley Blauwet of Dudley Blauwet Gems in Louisville, Colorado. Theoretically, treatment is repeatable “but usually irradiation is cost effective only when done on large lots of gemstones and not on single gems,” says Larson, who notes it would be too expensive to re-treat a single stone unless it’s added to another rough lot undergoing treatment.

PHOTOSENSITIVE

The problem — and it is a big problem — is that irradiated kunzite is known to bephotosensitive and can lose its color after exposure to light. Stones are also often unpredictable in how they will respond to radiation treatment, with some turning a deeper pink and others turning nearly colorless when treated. Some irradiated stones will fade even in darkness without exposure to light.

When Kunz and his fellow gemologists first began studying kunzite, they were unaware of this color instability and the fact that when exposed to UV rays, stones can permanently lose their color. The potential for loss of color varies greatly in a few days of strong sunlight, depending on the stone’s origin and treatment, but the flaw is significant enough that it scares away consumers, collectors and investors. “Kunzite does fade in direct sunlight. If someone has a kunzite ring and goes to the beach wearing it, it’s pretty grim,” Larson says. A safer rule of thumb: Treat the pretty pinkish spodumene as an evening stone, best worn at dinners and cocktail parties. Some of the material is actually prefaded, so the average customer could own it for five or six years with no noticeable difference.

The origin of an irradiated stone also may help determine its color stability. For example, Blauwet notes that Brazil and Bangkok may have more efficient treatment techniques and stones treated there may hold their color better than stones treated in Pakistan. While there is no laboratory test to predict color loss in light, it does appear that untreated natural kunzite, such as that from Southern California, tends to be more UV-resistant than treated kunzite.

“In terms of natural kunzite, I’ve seen it be relatively stable, with some slight fading of 5 percent to 15 percent over years,” Blauwet says. He adds that “The color can be really quite stable if it hasn’t been treated. Some kunzite rough tends to be more stable than others.” Designer and manufacturer Abraham Wolf of Lindsay Wolf, Inc. in New York City has seen large high-end kunzite stones hold their color for up to 20 years. “I personally don’t think every stone is photosensitive. I think certain natural ones don’t lose color.” There is no lab test to confirm whether a stone is natural or irradiated and determining which is which often boils down to a “hunch” developed through years of expertise.

A CUTTING CHALLENGE

Kunzite also poses a challenge to cutters. The stone has two directions of perfect cleavage so if you cleave it at the wrong point, it can split in two. Mauthner adds, “We have cutters who are very skilled working with kunzite, and they’re willing to take it on. I have a number of cutter friends who just won’t work with it, which is too bad because once you get a handle on it, it’s a really nice stone.”

“In today’s market, there’s a lot of interest in semiprecious stones and in gemstones generally,” Wolf says. “The fun part of kunzite is to talk about it,” Larson says. “You’re selling to intelligent people who buy for price, or to someone who really understands what it is.” Due to its unique, lovely color — and the interest collectors have in high-end stones — kunzite is never going to be commonplace or ordinary.

Article from the Rapaport Magazine - August 2012. To subscribe click here.

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