VALUE JUDGMENT As competition grows, the amateur mineral collector is giving way to a breed of more serious, professional mineralogist who enjoys the challenge of studying the chemical and geological elements and processes that create rare, beautiful rocks. While there is an appeal in acquiring your own pieces, it is difficult to keep up with this heated market where the collectors are steadfast and sophisticated and the sales are anything but sedentary.

But in today’s market, the amateur mineral collector is giving way to a more serious, professional approach. While collecting on one’s own retains appeal, newcomers will find it difficult, if not impossible, to compete. Also, many working professionals, like Weill, lack sufficient time to study the market and track new opportunities. The Tucson show, for example, has expanded to about 40 separate venues and requires some three weeks to cover more than 3,000 dealers. Many new finds come from expanding commercial mining operations in emerging countries. When local miners discover a lode they think mineral collectors might want, collectors or, more often, their experts often fly in to make firsthand assessments and advise miners on how to extract the pieces without damage. Expanded digging in China, India, Africa and the Middle East adds to the logistical difficulties associated with appraising a new find.

George Harlow, the curator of minerals and gems at the American Museum of Natural History’s Department of Earth and Planetary Sciences, fields queries from international mineral hunters. Recently, he received a request from a Pakistani gem company asking if locals had unearthed a new variety of jade. They shipped Harlow a sample and, upon preliminary examination, he assured them it was nothing new. He admits that he is not in the hunt to acquire the best new finds because he has a limited budget. Acquisitive private collectors employ mineral scouts to analyze new finds on-site and buy them on their behalf. Since 2001 and the beginning of the war in Iraq, this has become an increasingly risky assignment—particularly in the Middle East, Afghanistan and Pakistan. "The danger is to Westerners," Harlow says. "The dealers go to Peshawar, some go up to the Khyber Pass, but the lunatic ones try to get to the mines."

Crystal Blue Persuasion
For Weill, gaining access to new discoveries has been vital to creating a high-quality collection in a short period of time. To accomplish this, he partners with Tanjeloff and mineral scout Daniel Trinchillo, who travels the world to investigate new finds. With their help, Weill acquired a rare stibnite, a metallic gray mineral, from Jiangxi Province in southeastern China; it is the largest specimen of its kind outside China. Last spring, Weill donated the mineral, which began forming 130 million years ago, to the American Museum of Natural History. Weighing nearly 1,000 pounds and measuring almost 4-feet long, with hundreds of swordlike crystals more than 10 inches in length, the piece is both rare and arresting. "Part of the goal is to have objects that tell a story and inform about the natural world, and this is kind of an eye-candy hook—once you see it from a distance, you’re drawn to it," Harlow says.

A MORGANITE specimen offered at Bonhams & Butterfields’ Natural History sale in June sold for $72,000. (Photograph by Bonhams & Butterfields.)

Weill is particularly drawn to beautiful crystals—like the huge aquamarine, valued at approximately $150,000, that he bought from a Pakistani mine. Most hexagonal aquamarine crystals range from 1 to 2 inches in length, but Weill’s specimen stretches to more than 5 inches, enhancing its rarity and value. He also bought one of the largest known blue tourmalines directly from a Brazilian mine four years ago for about $450,000. It is unusual not only because of its quality, color and clarity, but also for the striking 12-inch-long crystals (they commonly grow to just 2 to 3 inches). Today the tourmaline, on an unusual base of quartz, lepidolite and albite, is worth more than $750,000.

Like all serious mineral collectors, Weill focuses on rare and unusual examples, which tend to remain in demand and hold their value. But he admits to an aesthetic prejudice, too. "They’re prettier to look at," he says. Indeed, showy rocks have better resale value and have also found a market among noncollectors. There is new appeal among interior designers looking for signature and natural art pieces to place in clients’ homes.

When considering a new piece, collector Marc Weill asks himself four questions: 1. Is it in his collection already? 2. Does it complete a suite in his collection?(For example, he gathers tourmalines from all over the world and has examples from Pakistan, Afghanistan and Brazil.) 3. How perfect is it? 4. And is the price cheap or expensive for that particular piece? But when weighing the final decision, Weill says, "You’ve got to collect what you like."

"What we excel at in particular is selling specimens with high aesthetics," Florian says. "And I’ve tried a little bit of everything. We have tried selling minerals that are not that beautiful, but are rare and mineralogically interesting. But at the end of the day, it is just a big black lump for certain things, and it just doesn’t sell that well."

The rarest pieces show the greatest appreciation. These tend to be pieces from well-known mines that were completely worked out and are no longer available. The bright-red rhodochrosite in Weill’s collection, for example, found in the Sweet Home Mine in Alma, Colo., boasts classic, strawberry-colored crystals and is prized by collectors in part because the mine is closed. Exceptional size, clarity and condition enhance value as well, while white dings, or chips in the crystal, will detract. Minerals in situ, or attached to the rock matrix they formed in, also demand higher prices. Both semiprecious and precious minerals are valued in part for their appeal as cut rocks, but when the crystals show the same properties in their natural state, their prices can increase 10 to 20 times.

Focusing on the best examples he can find, Weill has helped raise the value of his collection. He estimates the value of his assemblage has risen between 10 and 20 percent per year, but he clearly enjoys more than the financial gain. He excitedly points to an enormous, smoky quartz crystal that he picked out during a trip to inspect a Brazilian mine two years ago. "That was found in this huge cavern in Brazil in a mine where they have 20-foot crystals like that," he says.

Elizabeth Harris is a staff writer for Worth.