Rare Keweenaw minerals up for auction Sat.

DALLAS – A rare piece of silver from the Keweenaw is among several Upper Peninsula specimens being auctioned off in Dallas this weekend.

Heritage Auctions is holding a Nature and Science Signature Auction including the Hoppel Collection, which made a $3.8 million debut in June.

The silver specimen, expected to fetch more than $38,000, was mined sometime prior to the 1930s, and eventually became part of the Wayne State University collection. The actual date specimens are mined can be difficult to find, said James Walker, director of nature and science at Heritage Auctions.

“A lot of these came out in miners’ lunchboxes,” he said. “They don’t necessarily surface for purchase at the time of production. Miners keep them around for years before they sell them.”

It competed with minerals from two other Michigan universities in a “beauty contest,” Walker said.

“A couple of the universities got together for an informal competition where they would exhibit their better pieces,” he said. “In silvers, this was the winner.”

The collection of more than 2,000 minerals was assembled by a Midwest industrialist from the early 1990s through the early 2000s, who used Hoppel as an alias. He aimed for variety and appearance, Walker said, unlike collectors with a narrow focus. As a result, the overall quality is “very high,” he said.

“He had the money and the eye for him to select things that are more aesthetic than the average,” Walker said. “It’s an excellent – almost ideal – collection for auction.”

Universities and museums usually aren’t part of such auctions, instead acquiring minerals by trade – as happened with Wayne State University, Walker said.

Michigan Technological University’s Seaman Mineral Museum will not be participating in the auction, said museum employee Monica Rovano.

The collection includes 10 pieces of Upper Peninsula minerals, including a crystal fan of copper and silver intergrowth from the White Pine Mine expected to sell for $7,500.

“The combination is really not all that commonly encountered,” Walker said.

“There’s a couple of other places on the planet you’ll see it, but not like Michigan.”

The specimen is rarer because it was taken from a mine, protecting it from glacial abrasion, Walker said.

Another piece is a 66-pound nugget of float copper broken off from the Keweenaw Peninsula by glaciers. The nugget, which has an estimated value of more than $3,000, retains traces of malachite.

Most of the pieces of float copper have traditionally been found by farmers. Now, it’s more likely to be people with metal detectors, Walker said.

“That has gone so far now that there will be people diving in near-shore areas of the peninsula, looking for things in the lake,” he said.