Man credited with discovery of 'Yooperlite' rocks in Michigan

(WJBK) - They're found along the shores of Lake Superior, they glow under certain UV lights, and they've been sitting there for who knows how long - until now.

A man in Michigan's Upper Penninsula is being credited with the discovery of a new kind of rock that he's calling 'Yooperlites', a name given to the rocks based on the term for people from the U.P.

Erik Rintamaki is a self-proclaimed 'rock-hound' and last year, he hit a beach along Lake Superior with a UV light. He made the discovery then and told UpNorthLive that he sold them to Michigan Tech University.

"They sent them out for testing and they contacted me through emails and told me I probably had something new that had never been found in Michigan before, and I ended up being published in the Mineral News in 2018 for that discovery," Rintamaki said.

In the article, which Erik sent to FOX 2, he said he and his brother-in-law had always wanted to hit the beach to see how the rocks on the shore would interact with the UV light. That was 15 years ago. He said he finally bought a UV light on eBay and made two small discoveries.

Now he's upgraded to a bigger and better UV light and has found stones as large as five pounds. 

When the UV light is pointed at the rocks, they glow vibrantly. Then when the lights are taken off, they continue to glow. It's spectacular on video - and probably even more so in person. Check the YouTube video Erik posted below.

While he's calling them Yooperlites, geologists said they're Syenite rocks that are rich in Sodalite. 

“So what that is, is just a beach granite or basalt that has a fluorescent mineral in it called Sodalite that they believe was brought down from Canada by glaciers," Rintamaki said.

Erik has collected dozens of the rocks and sells them for $32 per pound. Erik also has tours to help people find the rocks at $50 per person. 

If you want to buy a Yooperlite or go on his tour, check out his Facebook page.