The mystery of the stones glowing like fire in Lake Superior

Yooperlites, also known as Glowdalites, are luminescent rocks found in the Upper Peninsula of Michigan . They are a type of syenite that contains high concentrations of sodalite , a mineral that glows under ultraviolet light. Yooperlites come in a variety of colors, including orange, yellow, green, and blue.

Yooperlites were only discovered for the first time in 2017 by Erik Rintamaki, a gem hunter in Michigan. At that time, Rintaki was searching for rocks on the shore of Lake Superior at night using a UV flashlight to look at rocks, when he noticed some rocks glowing brightly with many different colors.

He had never seen anything like them before and decided to send some samples of his findings to Michigan Technological University and the University of Saskatchewan for analysis. They confirmed that the rocks are syenite with sodalite inclusions and that they were likely formed about 1.1 billion years ago during a period of volcanic activity.

Researchers from Michigan Technological University and the University of Saskatchewan studied and analyzed the above stones to try to understand their composition and origin. In a work published on Mineral News , they announced that the rocks were simply syenite containing sodalite. It contains several minerals, such as microcline feldspar, Sodalite, nepheline, cancrinite and pyroxene. All are responsible for giving Yooperlite its distinctive glow when exposed to UV light.

Rintaki decided to name them Yooperlites , after the slang term for people living in the Upper Peninsula of Michigan (UP), also known as Yoopers. He even trademarked the name and began selling the stone online and at shows. He also gives tours and workshops to teach people how to find and identify Yooperlites. His discovery caused a lot of interest and excitement among rock music lovers and the media.

But why do these rocks glow ? As noted above, that's because they contain high concentrations of sodalite , a blue mineral that belongs to the silicate group and is often found in igneous rocks, like syenite and granite, that form from molten magma. Yooperlites look ordinary in daylight, but when you shine UV light on them, they reveal their hidden beauty.

Yooperlites can be found primarily along the shores of Lake Superior in Michigan , especially in the Grand Marais, Paradise, Whitefish Point, and Brimley areas. They can also be found inland in some places where glacial sediments have carried them. According to information from Earthlymission , they can also be found in most of the Great Lakes of the United States and even scattered in various places around the world. However, finding them is not easy because they mix with other rocks and gravel.

To the naked eye, these stones - made of oxygen, silicon, chlorine, sodium, and aluminum - appear bluish-gray with white flecks. Therefore, it is often used in mosaic products, but when placed under long-wavelength ultraviolet rays, sodalite will light up, making the stone show red-yellow veins that look extremely magical.

The best way to find Yooperlites is to use a UV flashlight with a wavelength of 365 nanometers (nm), which is the optimal frequency for achieving sodalite fluorescence. You also need to search at night or in dark conditions , as daylight will take away their glow. You should wear protective glasses and gloves when handling sources of UV rays, as they can harm your eyes and skin.

When you spot a glowing rock, you can pick it up and examine it more closely. You can also use a loupe or magnifying glass to see the details of sodalite crystals. You may be surprised by the variety of colors and patterns that Yooperlites display under UV light.

Yooperlites are formed through a combination of volcanic eruptions and glacial movements. They formed about a billion years ago when a period of spectacular geologic violence saw North America try to tear itself in two. A rift between the continents formed, creating unimaginable volcanic eruptions and 360,000 cubic miles of lava - an eruption that created a lava ocean more than 1,700 feet deep. Despite this activity, the rift ultimately failed to divide North America, most of which lies beneath present-day Lake Superior. The last ice age about 10,000 years ago swept these glowing rocks south, leaving behind the Yooperlite blocks we find today.

Be careful, however, as collecting rocks in national parks or national lakeshores is prohibited by law. You also cannot collect and keep Yooperlites from private land without the landowner's permission. The same goes for historical sites such as parks or designated conservation areas.