RIVERTON - Discovery of a 34-pound opal in central Wyoming could ignite an old-fashioned, rootin'-tootin' mineral rush this week - if would-be prospectors get worked up about the find.
At 11 a.m. Friday, the Wyoming State Geological Survey will announce the location of a large opal deposit in central Wyoming.
"We've already had two to three dozen calls today," said Dan Hausel, a state geologist and one of the authors of a 12-page report that includes a location map and photos of opals from the site, weighing in at
11, 25 and 34 pounds.
"It is a fairly sizeable deposit," Hausel said. "It is covered by a lot of dirt, like the Australian deposits, so it will take a fair amount of digging to determine what's really there."
The giant opals dug up by Hausel and his associate, Wayne Sutherland, are common opals and not valuable in and of themselves. Yet the discovery of the opal fields raises the possibility - and prospector hopes - that the deposit will host substantial amounts of fiery orange opal and precious opal.
Hausel and Sutherland have seen fiery opal and traces of precious opal at the undisclosed site.
"The traces of precious opal indicates to us that there is the likelihood of finding more of that," Sutherland said. "…We think there's some real economic possibilities for the deposits."
Although Hausel wouldn't tip his hand about the location of the site, he confirmed that it is on federal Bureau of Land Management property. Sutherland said the site in a desolate, mountain area southeast of Riverton contains many outcrops of opal within a three-square-mile area.
The 34-pound chunk of opal from the site was brought back to the state Geological Survey office in Laramie, where it is on display.
Pam Stiles, of the BLM's Cheyenne office, said would-be prospectors shouldn't assume anything when seeking to file mining claims. For starters, she said, don't assume that the site is open to mining claims - it might be closed or withdrawn for a variety of reasons, such as wildlife habitat or cultural values.
"Secondly, they must find out whether there is a pre-existing mining claim already there," she said.
Federal land agencies like the BLM or the Forest Service have extensive records regarding mining claims on federal lands.
The laws governing mining claims haven't changed much since 1872, she said.
"It's first come, first served," she said. "If people think it's something major, they'll be out there knocking each other over."
There have been previous rushes to stake mining claims, she noted. As recently as the early 1990s, miners chased bentonite claims. The 1950s and 1940s saw miners rush after uranium sites.
Stiles said the Wyoming BLM office has mining claims for platinum, palladium, gold, jade and aquamarine, but no active mining for precious or semi-precious stones.
"There is a diamond mine down on the Colorado/Wyoming border," Stiles said, "but that's on private property."
Marion Loomis, executive director of the Wyoming Mining Association, said he has no clue what level of interest this opal deposit will have for prospectors or miners.
"It will be fun to watch," Loomis said.
Except for float deposits of jade in sands and gravels, there are no viable commercial mines focused on precious and semi-precious stones such as opal.
"It is always exciting when you hear about a new discovery," he said.
Today, Mexico and Australia are the dominant producers of precious opal, though the Roman Empire obtained opals from the Carpathian Mountains.
Hausel said the possibility of a rush motivated him to make the opal-location announcement at a scheduled time, to put everyone on a level playing field.
One Wyoming rockhound was skeptical that the new area will turn into a productive one for opal miners.
"I've never seen any fire opal here," said Melvin Gustin, who lives outside of Riverton and runs a small rock shop and jewelry business with his wife. "Now, that's what the world's seeking. I don't think it's worth claiming myself."
But Hausel has found the fiery variety, and he e-mailed a reporter images of rock with tantalizing streaks of iridescence.
"Well, I won't pooh-pooh this," Gustin said.
In the gem and mineral game, he said, there are always optimists willing to spend the few hundred dollars it takes to survey and stake a claim.
Melissa Connely, a geology instructor at Casper College, said opal deposits are found in many areas but are usually small and of poor quality.
Connely said she would withhold judgment on the Wyoming opal for now, but "I would be interested in taking a look."
Star-Tribune correspondent Brodie Farquhar can be contacted online at firstname.lastname@example.org.