Kunzite

Spodumene is not one of the retail jeweler's most talked-about gem materials, but its pink variety, kunzite, is certainly a recognized name. Although it's found in remote mining areas in places such as Afghanistan and Brazil, kunzite actually was discovered right here in the United States.

History and romance. The name of George F. Kunz shows up in most of the late 19th-century and early 20th-century gemological literature. As Tiffany & Co.'s gemologist and later its vice president, Kunz was not only intimately involved with gemological purchases for the company but also the author of some of the most important gem books of the time. At the age of 23, he supervised the cutting of the Tiffany diamond, a 128.51-ct. modified square antique double brilliant—the world's largest faceted fancy yellow diamond.

As a mineralogist, Kunz worked with wealthy financier and avid mineral collector J.P. Morgan. He helped Morgan amass many incredible collections, one of which was donated to the American Museum of Natural History in New York. Working for Tiffany, Kunz was instrumental in bringing the newly discovered Yogo Gulch Montana sapphire to the market, as well as many other U.S. gems that eventually wound up in Louis Comfort Tiffany's Art Nouveau jewels. He even helped persuade Tiffany & Co. to purchase a turquoise mine in Arizona.

Two of Kunz's books—Book of the Pearl (1908) and Ivory and the Elephant (1916)—were considered the most comprehensive treatments of those topics at the time and today are considered classics of gem literature. The Curious Lore of Precious Gems (1919) is still the authority of choice when questions arise concerning birthstone legends and traditions.

Pink spodumene was found in 1901 in the Pala region of San Diego County. After the material stumped gem experts in San Diego and Los Angeles, rough crystals of the pink gem were sent to Kunz. He identified the material as spodumene, and in 1904, the material was given the name "kunzite." There's a certain irony to the name: At the time, Kunz was trying to contact Morgan to ask about naming the pink spodumene "morganite." Not hearing from Morgan, the University of North Carolina professor of mineralogy, Charles Baskerville, went ahead and had the gem named after Kunz. Fortunately, pink beryl was being discovered in the same locality at the same time, so Kunz quickly gave Morgan a second shot at mineralogical fame, and pink beryl became "morganite."

Qualities. Kunzite is expected to be eye-clean of inclusions, so like all clean gems, the color of the stone is most important. But cutting a kunzite to reveal its best color is difficult.

First, kunzite has two perfect cleavage directions on which it could break. Second, kunzite seems to have a resistance to being cut, even though its hardness is only 6.5 to 7 (relatively soft, similar to quartz). But because of its growth structure—specifically its cleavage directions—it takes much more patience and better tools to cut through and polish a kunzite crystal. According to kunzite expert Gary Bowersox, owner of GeoVision in Hawaii, it's best to use a cutting wheel that will reverse so you can go against the grain if the rough starts to peel.

Third, kunzite's strong pleochroism means that it must be cut in the direction of best color, which is almost always perpendicular to the length of the crystal. This is disappointing for most cutters because in this direction the crystal is narrow. Looking down the length shows the beautiful lilac color, but looking through the width of the crystal will most often show a very light pink, nearly colorless gem.

Color variations. Kunzite is a lavender or lilac pink. In Liddicoat's Handbook of Gem Identification, kunzite is included under the pink, red, purple, and violet gem lists. Some describe it as bluish-purple, reddish purple, and even purplish-red. The more saturated colors are preferred.

Kunzite is usually cut in large sizes. Much of the more common rough crystals have such light coloration that the gem must be cut deeply before the more saturated color appears. A smaller gem with saturated color is a rare find. It is not uncommon to see 10-, 20-, and even 30-ct. stones.

Natural-color morganite and kunzite can fade from heat exposure via too much direct sunlight or showcase spotlights. These pink gems are often called "evening gems," emphasizing the need to keep them out of the daytime heat.

Enhancement. While it is possible to create pink spodumene through a complex process of heat and irradiation, the color of such gems is totally unstable, and it doesn't take much light to put them right back to their original light brownish-pink color. So never buy kunzite in a hurry: Always allow time for the stone to show you its true color.

That said, if you have a kunzite that has lost its color because of heat or light exposure over the years, it may be possible to restore the color through this irradiation-and-heat process.

Pricing. For fine quality kunzite of five to 20 carats, average prices can range from $45 to $75 per carat. For extra-fine gems, expect to see prices ranging from $70 to $90 per carat.

Care and cleaning. Because kunzite has such delicate color, customers should be taught how to protect it. Keep kunzite out of direct sunlight if possible. Don't wear kunzite to the beach or poolside, unless it happens to be an evening event. Cleaning can be accomplished using a soft toothbrush and jewelry cleaner, but be sure to wash off any dust before wiping the gem clean, as dust will scratch and dull the polish. Use of home ultrasonic units should be avoided.

Bench repair and setting. Always protect kunzite during a repair. If it can easily be removed from the mounting prior to repair, this is the preferred method. Kunzite should be protected from any kind of shock, including heat, pressure, and vibration. Steam cleaning and ultrasonic cleaning are not recommended.

Recommended reading. For more information, see:

Gems by Robert Webster, Butterworth & Co., 1997.

Gem & Crystal Treasures, Peter Bancroft, Western Enterprises/Mineralogical Record Books, 1984.

Special thanks to Gary Bowersox of GeoVision Inc., Honolulu, Hawaii; (800) 544-4037, www.gems-afghan.com.