Ever thought of adding an extraordinary rock to your collection? Consider Yooperlites, a fascinating recent discovery.
Yooperlites, also known as Glowdalites, are fluorescent rocks found in Michigan’s Upper Peninsula. These rocks are a type of syenite that contains a high concentration of sodalite, a mineral that glows under ultraviolet light. Yooperlites exhibit a range of colors, including orange, yellow, green, and blue.
The Discovery of Yooperlites
Yooperlites were first identified in 2017 by Erik Rintamaki, a rock enthusiast from Michigan. While searching for rocks along Lake Superior’s shore at night with a UV flashlight, Rintamaki noticed brightly glowing rocks in various colors. Intrigued, he sent samples to Michigan Technological University and the University of Saskatchewan for analysis. These institutions confirmed the rocks were syenite with sodalite inclusions, likely formed about 1.1 billion years ago during volcanic activity.
Rintamaki named the rocks Yooperlites, inspired by the slang term for residents of Michigan’s Upper Peninsula, also known as Yoopers. He trademarked the name and began selling the rocks online and at shows. Additionally, he organizes tours and workshops to help others find and identify Yooperlites. His discovery garnered significant interest among rock enthusiasts and the media.
The Glow of Yooperlites
The unique glow of Yooperlites is due to their high sodalite content. Sodalite is a blue-colored mineral often found in igneous rocks like syenite and granite, which form from molten magma. While Yooperlites appear ordinary in daylight, they reveal a stunning glow under UV light.
Yooperlites are primarily found along Lake Superior’s shores in Michigan, especially in areas like Grand Marais, Paradise, Whitefish Point, and Brimley. Some can also be found inland where glacial deposits have carried them. Although some sources suggest they can be found across the Great Lakes and even worldwide, finding them can be challenging as they blend with other rocks and pebbles.
How to Find Yooperlites
To find Yooperlites, use a UV flashlight with a wavelength of 365 nanometers (nm), the optimal frequency for sodalite fluorescence. Searching at night or in dark conditions is best, as daylight can wash out the glow. Wear protective eyewear and gloves when handling UV light sources to protect your eyes and skin.
Once you spot a glowing rock, pick it up and examine it more closely. Using a magnifying glass or loupe can help you see the details of the sodalite crystals. You’ll be amazed by the variety of colors and patterns Yooperlites display under UV light.
Legal and Ethical Considerations
It’s important to note that collecting rocks within national parks or lakeshores is prohibited by law. You also cannot collect and keep Yooperlites from private land without the landowner’s permission. This rule also applies to historical sites and preservation areas.
Even if you can legally collect them, consider the value of leaving them in nature. Admire them, take a few photos, and leave them for future generations to enjoy.
