Behold ‘Yooperlites,’ newly-discovered glowing treasures in Michigan’s Upper Peninsula

BRIMLEY, MI – You don’t have to look very hard to find natural beauty in Michigan’s Upper Peninsula, but if you know where to look, you may find a hidden treasure resting beneath your feet.

Behold “Yooperlites.”

Brimley resident Erik Rintamaki has cornered the market on the fluorescent minerals found along the shores of Lake Superior. He named them. He collects them. He sells them. And, armed with a powerful UV light, he leads tours to show other rock hounds where to find them.

“I’ve been a rock hound all my life,” he said. “It runs in the family. Once you start finding cool rocks on the beach, it gets addicting.”

“Yooperlites,” and other similar sodalites have likely been in Michigan for centuries, left behind by glaciers and rounded by the wave action on Lake Superior. But Rintamaki has been credited publicly with discovering this particular variation in Michigan, which includes a Hackmanite-like fluorescent quality.

Testing completed at Michigan Tech University confirmed the presence of sodium, aluminum, silicon, chlorine and oxygen, but no structural sulfur, which likely results in the fluorescent properties of the mineral, according to Kevin Cole, associate professor of geology at Grand Valley State University.

The rocks have a mesmerizing, out-of-this-world glow when hit with high-powered UV lights, something Rintamaki discovered when he first encountered the mineral in June of 2017.

“I left for the beach at 4 a.m. and arrived just in time to use my cheap 3 LED longwave UV flashlight,” he recalled. “I found two very small Yooperlites about the size of a dime. I went four more times and only found a half dozen stones.”

“Then I upgraded to a 100 LED UV torch and that’s when the fun began. My largest find so far has been five pounds. Now I have upgraded even further to Convoy S2+ UV and a shortwave lamp. So I hope to open even more secrets of our Lake Superior beaches.”

Armed with knowledge and equipment, Rintamaki has become known for his ability to find the glowing treasures. He routinely leads guided tours throughout Luce and Chippewa counties. Two such tours are scheduled to take place at Muskallonge State Park on Sept. 8 and Sept. 9.

The attention Rintamaki has brought to the presence of the fluorescent sodalite has led others to study the mineral. It is now believed to naturally occur in kilogram quantities along Lake Superior beaches, meaning it is readily available for collection.