TUCSON, AZ (Tucson News Now) - More than 55,000 people are in town for the Tucson Gem, Mineral and Fossil Showcase.
Among the thousands of shoppers and vendors are a handful of undercover federal agents on a mission to stop an international criminal threat.
The Homeland Security agents work hand-in-hand with Interpol, looking for national treasures stolen from around the globe and brought here to be sold on the black market.
MOBILE USERS: Photographs of some of the priceless items recovered from around the United Stated can be seen HERE.
Even before the tents are up, these agents know exactly what they're looking for.
In the international marketplace that is the gem show, your eyes may be focused on the sparkling amethysts, dinosaur bones and other treasures dug up all over the world.
What you won't see are the trained eyes focusing on the vendors.
"We are looking at individuals, known individuals who are suspected of trafficking in these types of goods," said Chad Plantz, assistant agent in charge for Homeland Security Investigations, Tucson.
Operations like this one have been invaluable in unearthing valuable cultural property that should not be here.
Since 2007, these agents have seized 8,000 items taken illegally from 30 countries.
Once seized by agents, the items are then returned to their homes, with great pomp and circumstance at repatriation ceremonies.
Agents told KOLD News 13 most of the "shady deals" are done in smaller private shows, away from the public's eye.
Plantz discussed some of the items seized in the past during the gem show.
Dinosaur eggs that are 130 million years old. Burmese rubies. Seven tons of rare fossils smuggled out of Argentina, discovered hidden in 55-gallon drums.
"It's pretty significant for the countries that have lost these culturally significant items," Plantz said.
Homeland Security agents said while most of the dealers here are legitimate, they're working to make sure nothing you buy here was looted or produced through child labor.
KOLD 13 tried to talk to fossil dealers, but many wanted nothing to do with our cameras and some asked us not to take video of the items on sale.
However, the vendors said they support the work of the agents.
"Every time one of these clowns brings something into the country illegally, or it's a fake, it debases all of us," said Ken Campbell with Crystal Universe AusRocks.
Federal officials declined to say who or what they were looking for during this year's show as it is all of part of an ongoing investigation.
They did say they received some tips and are hoping to make some good finds.
KOLD News 13 will update this report as soon as we get that information.