Erik Rintamaki, 43, of Brimley, considers himself an amateur rock hound who has been on a wild ride, all because of some beautiful fluorescent specimens.

Rintamaki said he was out on a Lake Superior beach last summer trying to find some agates, and after three trips, he didn't find anything — but on his fourth, he stumbled upon three tiny fluorescent stones the size of a dime.

"You could hear me screaming all the way down the beach, and I got home, Googled it and couldn't find anything that looked like it," Rintamaki said.

Rintamaki said he ended up getting the speckled stones up into the hands of geologists from Michigan Technological University around December and was told he may have stumbled upon something that has never been seen in Michigan before.

After rounds of testing and analysis, Rintamaki said the rocks were sent off to the University of Saskatchewan, which backed up the Michigan Tech geologists' findings.

While Rintamaki told the Free Press that he's probably not the first person to have ever stumbled upon these glowing rocks on Michigan beaches, his was the first discovery analyzed and confirmed by geologists.

Thus, Rintamaki was credited with the first verified finding of sodalite-rich syenite rocks in Michigan and was published in the Mineral News in 2018.

Following the finding, Rintamaki came up with the name "Yooperlite" and started up the Yooperlites Facebook page.

"I wanted something that represented where the rocks come from," he said.

Since starting the conversation on social media, Rintamaki said he's enjoyed seeing people's Yooperlite finds from all over.

"A guy down by Chicago found them on Lake Michigan. Somebody found them downstate at Point Betsie Lighthouse the other day," he said. "You have to have a long-wave UV flashlight or torch to go out at 365 nanometers, that's the nanometer that works best. ...

"They glow a super-bright orange, they look like you're holding lava in your hand."

After taking a couple of people on his first Yooperlite tour last year and taking his friends out looking for the rocks, Rintamaki said he had so much fun he started offering tours on his Facebook page.

The Yooperlite night picking tours, priced at $50 per person, include "a guided tour for Yooperlites and a UV torch light that you get to keep."

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He hosts them on his days off, Sundays and Mondays, and plans to keep them up until it gets cold. Rintamaki says the average season for night picking is from the middle of May through the end of October — but tours for this season have now sold out.

Rintamaki said the tours really took off after a friend, Wanda Stevens, shared the tours on a Facebook page aimed at people who love looking for stones on the weekends.

A group set up a tour, and Rintamaki videotaped their reactions to finding Yooperlites for his own Facebook page. One of the videos went viral.

To date, the video Rintamaki shared of Shirley Klemmer finding her first Yooperlite has 1.2K shares and over 90K views.

"That video is what has catapulted this thing into the stratosphere," Rintamaki said.

One of his favorite things to do on tours is to meet people, learn their stories and share his own, Rintamaki said.

Although he actually has a music degree and works at a casino full-time, Rintamaki told the Free Press he has been a rock hound his whole life — he still has the first rock he ever found.

"I was 1 week old and I went to the park with my dad," he said. "My mom painted it with my name on it."

Rintamaki said he can't believe how the Yooperlite craze has blown up so big, so fast.

He said he has sold more UV flashlights than anything, because so many people want to go out and find the glowing rocks themselves.

"That's the whole magic of these stones," he said.

For anyone looking to find some Yooperlites, Rintamaki recommends the following:

Always bring a white LED flashlight

Always bring essentials, like something to drink, a backpack and warm clothes

Wear hiking boots

Don't do it if you have an impairment, like a bad hip or a bad knee

Use glow sticks to mark your path, make sure you don't get lost on the beach at night

Rintamaki said there are also a few visual markers that set Yooperlites apart from "fakers" on the beach.

"There are lots of stones that fluoresce on the beach, but they don't fluoresce like a Yooperlite. A Yooperlite ... it's like seeing the sun on the beach. They glow so bright."

There are a number of different patterns that can be used to identify a Yooperlite as well, Rintamaki said:

Spray paint-like patterns, with tiny speckles everywhere

Flower-like patterns with plumes

Striations that look like veins running around the rock



Rintamaki said anyone interested in fluorescent minerals might also be interested in checking out The Fluorescent Mineral Society, which provides information about Yooperlites and other minerals that fluoresce.

Going forward, Rintamaki said he is working on setting up an official website and will be setting up an official eBay page to sell Yooperlites.

For more information contact Aleanna Siacon at asiacon@freepress.com. Follow her on Twitter: @AleannaSiacon.