In September 2009, David Booth, a park ranger in Stirling, Scotland, packed up his brand-new metal detector ("I practiced at home picking up nails and bits"), drove to a field, walked seven yards (six meters) from his parked car, and scored big. His first sweep with a metal detector yielded a spectacular find: four gold torques, or neck bands, from the first century B.C.—the most important hoard of Iron Age gold found in Scotland to date.

Several days later, Stuart Campbell of the National Museum of Scotland, the man in charge of "treasure trove" finds, as they are known in the United Kingdom, arrived at his Edinburgh office, opened his email to find a message with the subject "gold jewelry" and thought, "Oh, no, not another Victorian watch chain." Then he saw the images.

Thanks to laws in England and Scotland that encourage artifact hunters to cooperate with archaeologists, Booth was paid the current market price for the cache, about $650,000, set by the queen's and lord treasurer's remembrancer (the British crown's representative in Scotland). He split the sum with the landowner.

In England, Wales, and Northern Ireland, the Treasure Act of 1996 defines gold or silver finds older than 300 years as treasure and claims them for the crown. Finds must be reported within 14 days. Scotland's laws are broader: Treasure does not have to be gold or silver and can be less than 300 years old, but in both jurisdictions, a significant find will be offered to museums to bid on.

The spectacular hoard of Anglo-Saxon gold, silver, and garnet objects discovered in 2009 by Terry Herbert, an unemployed metal-detector enthusiast, was acquired by the Birmingham Museum and Art Gallery and the Potteries Museum and Art Gallery, Stoke on Trent. The assessed value of $5.3 million was split between Herbert and the owner of the Staffordshire field where it was found. (In December, about 90 more pieces of gold and silver were recovered from the same area.)

Britain's Amateur Treasure Hunters Strike Gold

Nearly 90 percent of archaeological artifacts in the U.K. are found by amateur treasure hunters with metal detectors. Michael Lewis, deputy head of portable antiquities and treasure at the British Museum in London, calls it "land fishing," adding that the law encourages treasure hunters to adopt best practices in metal detecting, such as recording the location of finds.

A related program, the Portable Antiquities Scheme, is a voluntary project, managed by the British Museum, to record archaeological objects—not necessarily treasure—found by members of the public. So far, the British Museum has documented 800,000 finds, everything from gold and silver artifacts to bits of pottery and iron. Taken in context and seen together, they give a picture of where and how people lived in the past.

The relationship between archaeologists and metal detector hunters is, for the most part, downright amiable. Each year, the British Museum reaches out to some 177 metal-detecting clubs and judges the year's "best" find.

U.S. Treasure Laws Lag

How do laws in the United States stack up? Fred Limp, president of the Society for American Archaeology, summed it up: "Basically, except for materials on federal land, state law applies and, with some exceptions, objects are the property of the land owner." There is no standard rule; it varies state to state.

Federal laws are strict. "A stone tool is property of the federal government in perpetuity," said Limp. "Its digging up is a violation of law and can be a felony." Depending on the state, the same object found on private land may or may not have protection.

In other words, "private landowners can dig up all the sites they want and sell on eBay," said Tom Green, director of the Arkansas Archeological Survey. A notable exception is burial sites. Nearly all states have laws forbidding the digging up of burial sites (where most of the best material is found—"like the good, fancy pots," explained Green).

What about exporting the British scheme to the United States?

"It wouldn't work here," said Chris Espenshade, a consulting archaeologist for Commonwealth Cultural Resources Group in Michigan. "It's contrary to our culture." It's the mindset of "It's my property and I'll do what I want" and an American individualism that expresses itself in "no trespassing" signs.

Furthermore, said Espenshade, "We don't have that kind of treasure in the United States. Most of the people out metal detecting aren't finding big money items. It's not a Celtic gold broach. It's a lead minie ball [an old bullet]."

Still, he admitted, the compensation afforded by the United Kingdom's laws mitigates the idea that a finder should give away a treasure and not get anything in return.

Limitations to the U.K. Treasure Act

The U.K. laws aren't perfect. Important finds have slipped through the cracks—notably a magnificent bronze Roman helmet found in Cumbria and auctioned off by Christie's in 2010 for $3.6 million to a private collector. (Because it was a single object and made of bronze, it didn't technically qualify as "treasure.")

But the laws seem to function well enough. Said Michael Lewis of the British Museum: "The Treasure Act works well because it ensures that important finds end up in museums for all to enjoy and that finders are rewarded. They are encouraged to do the right thing."