A SABER-TOOTHED cat skull found in China sold for $17,625 at a Bonhams & Butterfields auction last December. (Photograph by Bonhams & Butterfields.)

Lieberman, chief investment officer for Advisors Capital Management in Paramus, N.J., discovered this lucrative diversion almost accidentally while vacationing in Arizona and Utah. He was amazed by the variety of fossils he found for sale in a small curio store, including dinosaur teeth and claws. He bought his first pieces that day–some common, inexpensive fossilized fish. Today his collection is far richer. One of his prized items is an Eocene fossilized gar from the Green River Formation, an outcropping in Wyoming, Colorado and Utah. He bought it at auction 15 years ago for $3,400. He suspects it is now worth $25,000.

For rare, high-quality specimens, this type of appreciation is not uncommon. Prices for fossils are rising rapidly, driven by the growing number of admirers interested in acquiring these ancient artifacts for their home or scientific collection. Auction houses are moving to take advantage of this burgeoning demand. Christie’s featured its first stand-alone natural history sale in London in March. (Traditionally, fossils and minerals shared auction block billing with scientific instruments.) Bonhams & Butterfields, which regularly sponsors such auctions in Los Angeles, is planning its first New York sale in April. The market, experts agree, is gaining momentum. "It definitely feels like it’s on the cusp of being quite a big deal," says Tom Newth, head of the scientific department in Christie’s London office.

Important, museum-quality specimens have commanded millions of dollars for some time. Among the best-known specimens is "Sue," the largest, best-preserved Tyrannosaurus rex found to date; Chicago’s Field Museum purchased the fossil for $8.36 million at auction in 1997. Since the release of the Jurassic Park films in the 1990s, however, interest in fossil collecting has grown well beyond specialist institutions to include many individual collectors, as well. According to Thomas Lindgren, consulting director of Bonhams & Butterfields’ Natural History Department, much activity has come from new clients who are collectors in general, but who never were exposed to natural history in the past. New buyers are often attracted to the aesthetics of such fossils and are displaying them as natural art, drawn to what is truly unique. "It’s like the big-game hunters in the safari club group–they also like collecting trophy fossils," Lindgren says.

A PYGMY woolly mammoth fossil went for $104,750 at the auction. Private collectors are entering a field that was once the bailiwick of museums.

Prizing such objects may be nearly as old as man himself–trilobites have been unearthed at a Cro-Magnon site in France more than 10,000 years old. Later, some early collectors had religious affiliations. Around ad 400, St. Augustine dug mastodon fossils in North Africa, says Bob Bakker, a noted paleontologist and former university professor who is now a curator of paleontology at the Houston Museum of Natural Science. Bakker, credited with challenging the notion of slow, lumbering dinosaurs and arguing that they were instead warm blooded, has authored a number of dinosaur books, and is finishing his latest manuscript looking at early fossil hunters’ religious ties.

In the early 19th century, interest jumped. In 1824, Oxford geology professor William Buckland published the first scientific paper on dinosaurs, describing a "great fossil lizard" found in England. (The term "dinosaur" was coined in 1842 by a fellow Oxford professor.) Thomas Jefferson was another notable fossil enthusiast. Jefferson was so enamored by paleontology that he funded digs in Kentucky and charged Lewis and Clark to both retrieve fossils on their expedition and to look for mastodons, believing they might still roam in the West.

Fans of the Cave Bear
It is difficult to estimate the total value of recent sales of natural history objects. This diverse category includes everything from petrified wood to fossils. Moreover, for sale purposes, many auction houses categorize natural history specimens with other items–Sotheby’s lumps them with garden furniture, Bonhams & Butterfields with jewelry and gems. Popular items, such as fossilized shark teeth or small mineral samples, often sell for less than $10 at shops nationwide. The higher end of the market, however, caters to ardent collectors and larger budgets. In 2005, Bonhams & Butterfields boasted $3 million in natural history sales; Christie’s sold roughly $525,000 worth of items.

According to Lindgren, the market value of some high-quality fossils has doubled or tripled in the past decade. The value of large Madagascar calcite ammonites ranging from 18 inches to 2 feet long, for example, has increased from about $2,000 to approximately $5,000 since 2000, Lindgren says. Over the past 10 years, better-quality saber-toothed cats have risen in value from roughly $2,500 to $7,500; sale prices of La Brea Tar Pits-quality fossil cats have risen from $25,000 to $250,000. Lindgren claims the North American markets in particular have witnessed a great deal of interest. "Unique and exceptionally spectacular pieces or specimens will always escalate in value," he says. "You won’t always get a two- to three-times return in 10 to 15 years, but I’ve never seen a great specimen that has integrity or a really beautiful specimen go down in value."