BALTIC – About two dozen people spread across a massive rock pile Friday, focused on the rocks and potential treasures beneath their feet. Some walked slowly with metal detectors, while others knelt, hammering at promising rocks that years ago had been hauled out of the Baltic Mine and left behind as waste.

Jill Johnson from Superior, Wisconsin, showed off one of the most exciting finds of the day, a shiny, jagged, softball sized piece of chalcocite her husband David had just chipped off a specimen that would have been too large to carry.

“I’ll probably make it into jewelry,” said David, who’d spotted the sample by eye.

The Johnsons may have been assisted in their find by Keweenaw Mineral Days staff and volunteers, who’d gotten permission from the landowner to use heavy equipment to expose fresh finds that hadn’t been picked over by past generations of rock hounds.

“We come with an excavator, move rock around, skim off what everyone else has metal detected through,” said Ted Bornhorst, director of Michigan Technological University’s A. E. Seaman Mineral Museum.

The collecting event was one of about a half-dozen mineral collecting events held as part of the museum’s Keweenaw Mineral Days, a week-long event co-hosted by Keweenaw Gem and Gift that also included lectures, a silent mineral auction and mineral identification seminars.

About 120 people were signed up for Mineral Days, most coming from out of town and staying for four days or more, Bornhorst said.

“Mineral collecting in the Keweenaw is a hidden economy,” said Bornhorst, noting that rock hounds came in for the event from as far away as California and Georgia.

“A few years ago, we had someone from England who flew over,” he added.

The event has been going on for about 30 years in different incarnations, Bornhorst said, beginning as the Red Metal Retreat and going through a period where it was sponsored by the Copper Country Rock and Mineral Club before the museum took over about 10 years ago.

It’s scheduled in between a weekend of mineral events on the Iron Range around Ishpeming and Keweenaw Gem and Gift’s Evergreen Exploration, to help visitors get the most out of cross-country drives, he added.

Volunteer Larry Molloy said rock pickers at the Baltic site were mostly looking for copper and chalcocite, while other sites up the Keweenaw were good for greenstone and datolites.

“These really are one-of-a-kind specimens,” Molloy said. “You aren’t going to find native copper anywhere else.”

Jim Morrison, from Middleton, Wisconsin, said he’s been coming to Mineral Days and earlier incarnations for about 20 years, and now makes it a family affair with his wife and sons.

“It’s a unique experience, fun, and kind of a tradition,” he said.

Morrison said he’s mostly on the hunt for copper, but this year, both his wife and one of his sons found Indian hammer-stones, which Native miners would have used in pre-industrial excavations.

Jay Batcha, from Macon, Georgia, said he found a nice copper specimen, as well as some hematite and banded jasper during a stop in the Iron Range.

“I make guitar picks out of stone,” he said. “So I’m trying to find stuff I can cut wet.”

The picks subsidize a hobby that takes him all over the country, including a trip to Oregon just a couple of weeks ago.

Batcha’s mineral collecting career began with a trip to pan for gold in his native Georgia, where he also bought a few geodes he couldn’t cut with his hacksaw. The he found a good deal on some used cutting and polishing gear.

“Then I had all this rock equipment, so I joined a rock club, and here I am today,” he said.

Now, “my wife says my collection’s taking over the house,” he said. “It already did in the garage.”

Batcha said Mineral Days and similar events are great, particularly for out of town collectors. Not only does turing over the rock provide better access, the event also helps visitors find the good rock piles.

“This is the way to go,” he said. “Coming from out of state I don’t know where to go.”