Claim to fame: Lake Superior agates are the oldest agates on earth, formed 1.2 billion years ago. The next oldest are the Montana moss agates, a mere 370 million years old. Photo by Todd Zawistowski ...

The rock is lighter gray than the dark basalt that's more prevalent along the North Shore of Lake Superior. Both types of lava rock formed about 1.1 billion years ago, icelandite is relatively ...

Yooperlites are rocks that fluoresce under UV light. The best time to search for Yooperlites is after a storm, when waves may have unearthed new rocks along the shores of Lake Superior. Rock ...

The elusive Lake Superior agate. Rockhounds scour Lake Superior’s shoreline for these rare banded beauties—from the western reaches of the Keweenaw Peninsula to the U.P.’s easternmost ...

Yooperlites are most prominent along the shores of Lake Superior the Upper Peninsula, but can sometimes be found along the Grand Marais area, and the Keweenaw Peninsula, according to Pure Michigan.

Our kayaks sliced through the thick fog that blanketed Lake Superior, erasing any view of Split Rock Lighthouse towering on the cliffside ahead. We paddled past one of Minnesota's most ...