Searchers hunt for glowing Yooperlite rocks near Great Lakes

While the days continue to get shorter, the season for finding a specialty rock is in its final weeks.

Yooperlites – as they’re called – have been picked up along the shorelines of the Great Lakes for years.

Rock enthusiasts who collect them are called “hounders.” Ranging from the Wisconsin-Illinois border on Lake Michigan to the shores of superior near Duluth, these glowing minerals come from an Ontario glacier.

A recent stretch of warmer weather means more time to find yooperlites – or its scientific name – cyanide granite with florescent sodalite. It’s viewable with a UV light, and without it they just look like a normal rock. However, when you shine them with ultraviolet light, they fluoresce.

Since hounding became a viral sensation a few years ago, these nocturnal nuggets are becoming harder to discover.

See what they look like by watching the video from WJFW.