Why do the stones on the shores of the Great Lakes glow?

On the shores of the Great Lakes, you can find rocks that glow under ultraviolet radiation. This discovery was made by a group of geologists from Lake Superior University in the USA.

Experts have explored the shores of the Great Lakes and found that some stones there begin to shine if UV rays are directed at them. According to experts, it's all about the minerals in the composition of these stones.

In particular, unusual rocks are found on the shores of Superior and Michigan. Probably, these stones were formed as a result of geological processes that took place millions of years ago, when these territories were covered by the sea.

One of the minerals that can contribute to the glow is calcite. Depending on the composition and environmental conditions, it is able to shine in various shades.