Erik Rinktamaki has always loved rocks and spends much of his free time hunting for interesting ones on at a beach in his home state of Michigan. One night in June, he made a fascinating discovery – a rock that glowed. When he looked closer, he saw that the light emitted from cracks in the rock, like lava or a dragon egg getting ready to hatch. Upon returning home, he looked online for more information, but couldn’t find anything. What had he found?
Rinktamaki returned to the beach armed with a black light, which helped him find the illuminated rocks easier. He began collecting them, naming them “Yooperlites,” and selling them online for $32 a pound. The nickname “Yooper” refers to people who live in Michigan’s Upper Peninsula. One of the buyers, Michigan State University, wanted to study the rocks further. They confirmed that the gem hunter had indeed discovered a new type of rock.
People have most likely seen Yooperlites in Michigan for years, but no one bothered to get them studied before. Michigan State gave them a more scientific name, too, and says they are syenite clasts that contain fluorescent sodalite, which is a mineral. The most famous occurence of sodalite can be found in Greenland, where walks on mountain trails at night are illuminated by an orange glow. In the daylight, sodalite comes in a wide variety of colors, like yellow, green, and white.
The Michigan syenite-sodalite rocks most likely traveled by glacier down from Canada. In May of 2018, Rinkamite’s discovery was made public, and his business boomed. He sells Yooperlites to people from all over the world and guides night tours for those eager to find their own. If you find yourself by the shores of Lake Superior, be sure to bring your black light!