When I was nine years old, I visited my cousins in Reading, Pennsylvania. Knowing I’m an avid rock collector, my cousin excitedly told me we’d be seeing the crystal caverns!
He mistakenly believed the crystals would fluoresce in UV light but that got me thinking about other crystals and where a rockhound might be able to collect a rare specimen that would glow in the right environment.
Enter the stunning Yooperlites, otherwise known as fluorescent sodalite. Yooperlite is named for the residents of the Upper Peninsula of Michigan or Yoopers. Yooperlite absorbs light from UV lamps and expels it in a soft, orange glow.
What are these crystals? Are Yooperlites the same as other fluorescent crystals found all around the globe? Where can you find your own? Keep reading to find out!
What is Yooperlite?
Yooperlite is a variety of fluorescent crystals native to the Great Lakes region of Michigan. The crystal’s luminescence is visible when you expose it to ultraviolet light. Some rockhounds and specimen collectors claim the light emitted from the stone is similar to lava or space rocks burning on the shores of lakes and rivers.
Yooperlite is a registered trademarked name for a specific variety of fluorescent crystals from Michigan. It was first discovered and named back in 2017 by Erik Rintamaki. At the time, he was a mineralogist searching for large deposits of agate.
He believed that the agate’s bright colors would stick out at night by searching the shores with a UV light. However, he found a red, glowing fluorescent crystal resting on the banks of the Great Lakes.
These crystals are known scientifically as Sodalite-Syenite. These two distinct crystals joined together to make Yooperlite, a much sought-after mineral in Michigan.
- Sodalite: a rare variety of Feldspathoids
- Syenite: a common form of intrusive igneous rock primarily made of feldspar
When combined, these two igneous rocks create a luminescent stone. According to Molecular Expressions, these rocks are light-colored rocks and blend together to make an illuminating mineral that glows under ultraviolet light.
When you’re out rockhounding for Yooperlites you’ll notice they have small deposits of other minerals which alter their colors and translucent design.
Where to find Yooperlite rocks?
Yooperlite is found along the upper north peninsula of Michigan’s Lake Superior. It’s important to remember that these are just some of the variety of fluorescent crystals available but Yooperlite is a registered trademark term that refers only to fluorescent crystals found in this region.
According to My Michigan Beach, there are several spots along the shores of Lake Superior that are plentiful.
Great locations for finding and discovering Yooperlite
- Grand Marais
- Ste. Marie
The name “Yooperlite” comes from the name for residents of the Upper Penisula, or “Yoopers.” Yooperlite is a shoutout to these locals and is unique to crystals found in this area.
Yooperlite has grown in popularity as of late because of its’ unique qualities. On the surface, they’re very unassuming and are easily missed without the proper tools to spot them but when you hit them with UV light they really glow.
If you’re looking to add some unique rocks and minerals to your collection then you should think about planning a trip to the Upper Michigan peninsula to collect Yooperlites.
How Does Yooperlite Rock Glow?
Yooperlite glows through a form of luminescence which is a form of light absorption. These rocks have a unique composition that allows them to absorb and transmit UV light. In Yooperlite, this absorption is achieved through the presence of fluorescent sodalite.
Yooperlite is only one of many fluorescent crystal varieties. Fluorescent crystals or minerals differ significantly from regular crystals in composition and appearance.
However, fluorescent crystals do not reflect light instead, they absorb certain kinds of light.
As geology.com explains, fluorescent crystals glow due to a chemical reaction between sodalite and UV light. The UV light reacts with the atoms within the sodalite, activating them enough to produce heat.
You can watch this process illustrated perfectly in this viral video!
Does Yooperlite Really Glow in the Dark?
Yooperlite doesn’t glow in the dark, at least not on its own. Rather, Yooperlite absorbs ultraviolet light from a source and stores it within itself. This causes the rock to glow bright orange, yellow or red in dark rooms.
However, without UV light, Yooperlite will look like a normal rock you’d find in your garden or backyard.
Does Yooperlite Glow in Sunlight?
Yooperlite does not absorb energy or react with sunlight even though sunlight does have UV light it lacks the concentration needed to make a Yooperlite glow. The sun’s UV rays are mostly absorbed by the Earth’s atmosphere. UVB and UVC rays are almost entirely filtered out before reaching Earth’s surface which means we only receive UVA rays in significant quantities.
When using a UV lamp, the rocks receive a heavy dose of UV light which activates the atoms. Once the atoms become excited you can visually see the rock glowing.
What Should You Bring to Find Yooperlite?
The most important item to bring with you is a UV light because that’s the only tool that allows you to see if the rocks will glow. Now that you have a UV light on order from Amazon you’ll need to pack a couple of additional items for your rockhounding trip.
- Extra flashlight
- A headlamp
- Bag or backpack
- Extra batteries
- Snacks and drinks
Don’t forget cell service and visibility won’t be very good in some of these areas so make sure you plan and dress accordingly.