Yooperlites are syenite rocks rich in sodalite. They were discovered in 2017 in the Upper Peninsula of Michigan by Erik Rintamaki. Not knowing what type of rocks they were, he named them yooperlites. Although he was not the first to discover these rocks, he was the first to discover sodalite in Michigan. In normal light they look like plain grey rocks, however, when exposed to a black light they fluoresce.