"Yooperlite" vs “Sodalite” What's in the famous name? What are Yooperlites really?

Yooperlite rocks went viral a few years ago. When folks started shining their 365nm UV flashlights on the beaches of Lake Superior, they discovered bright, orange glowing rocks. After data was published on these fluorescent stones, it was discovered that they were actually a mix of several minerals - sodalite, an alkali feldspar, and a bunch others - usually referred to as nepheline syenite (an igneous rock containing several minerals). 

Sodalite is the actual true mineral that is fluorescing orange and is very often one of the minerals in syenites from alkaline complexes.  

These Yooperlites have been worn smooth by wave action over millions of years, and it is generally accepted that glacial activity transported them to the shores along the Great Lakes from the Caldwell Alkaline Complex in Canada. Meaning over time, these glaciers melted and carried these fluorescent stones down the mountains onto the beaches of the Great Lakes. 

They seem to be also found in Wisconsin, and maybe even Illinois. 

Yooperlite fluorescing under 365nm longwave UV light. Photo courtesy Erik Rintamaki, Fluorescent Minerals Facebook Group

They were nicknamed "Yooperlites" which is derived from the name “yooper”. A yooper is a nickname for the Upper Peninsula natives and these fluorescent stones quickly gained fame. There was a write-up in the Mineral News, the "discovery" was picked up by local news stations and then by CBS News, online posts went viral, and the rest is history. 

People started listing them on Ebay and they instantly were bid up over $100 for a little river pebble. It's the first rock fad we've seen since pet rocks! Personally we hope it grows and Walmart starts carrying them - what better way to spread the word about fluorescent minerals!?!

Many people discourage the use of nicknames, or inventing new names, for a rock. It causes confusion and is a grey area in the way of professional geology. We don't disagree but understand the reasoning behind the nickname Yooperlite. There is a certain amount of regional pride in the Upper Peninsula in the name.

But - it is a nickname for a rock with relatively common minerals (sodalite being the orange fluorescent mineral) that have been water-polished over centuries or more. There's a lot of misinformation floating around on the IDs. Many are calling it syenite. While true the "rock" is referred to as syenite, it's the "mineral" sodalite that is fluorescent. 

The orange "glow" is a common response of sodalite under 365nm longwave UV light and similar fluorescent sodalite can be found in Canada, Greenland, Norway, Afghanistan, and several other places around the world. If any of the localities in those places have a river running through it you will likely find this tumbled variety. I guess you could give it your own name, or call it a "Yooperlite Type" sodalite, or just call it what it really is - sodalite. 

Not to be left out, Greenland has its own “Yooperlite style rock” (but we just call them sodalite, or jokingly “Glooperlite”). Glaciers eroded sodalite out of the Ilimaussaq Complex and carried them towards the ocean, grinding and polishing all the way. Many were deposited in the glacial moraines near the village of Narsaq. Lots more can be found on the pebble beaches in the fjords cutting through the complex.

The sodalite is brightly fluorescent under 365nm UV light. In Greenland's Ilimaussaq Complex the combination is a basic rock-building assemblage- usually referred to as naujaite. The pic below shows 6 rocks, three of which are the result of splitting one larger rock to reveal the interior. When split, many (such as this one) exhibit a strong tenebrescence after exposure to shortwave UV (see animation below). This is (so far) a Greenland exclusive. Minerals include sodalite, arfvedsonite, aegirine, eudialyte, and probably a few others, all in a syenite type rock.

 Sodalite from Greenland that has been worn and tumbled by water and glacial activity

Pieces from Greenland look identical to the Yooperlites from Michigan with only a couple of exceptions: they are quite large usually, and they are often tenebrescent inside. The pics above shows the big rock split in two, before and after exposure to shortwave 254nm UV. Animation below shows it a little better.

A quick note on photography: Lots of new people (new to fluorescent minerals) are taking pics of these and selling online. They are using unfiltered, 395nm UV lights and taking the pictures on fluorescent backgrounds (white paper, colored backgrounds, etc). Some complain that it requires expensive lights to take good pics - but the $25 Convoy S2 works just fine. Here's a sampling of photos from Ebay: (in this comparison we’re just worried about the terrible purple haze. Sodalite, when overexposed, will appear yellow as seen in the last pic. It should be orange but we won't worry about that right now since most photos barely show any resemblance to the actual fluorescence these rocks deserve.)

Our personal opinion on the “Yooperlite” nickname?

Yes, “Yooperlite” is a made up nickname. But it is derived from a proud regional moniker and is fun to say. Hundreds, maybe thousands, of kids (and adults) are and will be searching for them on the shores of the Great Lakes. They will get off their screens, go outside and enjoy nature. 

Their parents will have to buy a Convoy and teach them about fluorescent minerals. That will result in an influx of new hobbyists not seen since the Convoy hit the stage three years ago (and will easily become the most important source of new members for our hobby - all-time. 

“Yooperlites” have dominated the conversation in our group many times. Some folks have been having a lot of fun, while others seem distressed by the somewhat trivial discussions. It is the most important development in our hobby since the Convoy UV flashlight development. From the Fluorescent Mineral Society website: “The mission of the Fluorescent Mineral Society is to bring together people who are interested in fluorescent minerals, and to introduce the public to the hobby of fluorescent mineral collecting. This mission is pursued by promoting fellowship and educational activities, and supporting research that increases basic knowledge of fluorescence and fluorescent minerals. Yooperlites have introduced far more people to our hobby than any other happening in recent history. Along with the Convoy UV flashlight, more folks can enjoy our hobby than ever before. We have seen thousands of new members join our Facebook group – a record. Howie coincidentally decided to run a promotion for new Fluorescent Mineral Society members and, by our count, has had at least 7 new members join the Fluorescent Mineral Society.

A few years ago, there were no Yooperlites offered on EBay. Today there are over 50, with many bid up to $50 or more. These are being listed in random categories instead of the fluorescent mineral category, further spreading the awareness of the fluorescent mineral  world to non-fluorescent collectors. 

Yooperlites have gone viral. There are at least 452 official news stories returned by Google compared to none a year ago. CBS News, MSN, dozens of local news stations, several write-ups in newsletters, dozens of videos on Youtube (one was even posted on WeChat in China), they’re even posted on Instagram already. On Reddit (“the front page of the Internet”) Yooperlites reached the front page (a major win) as one of the most popular topics and there are no less than 40 different posts made about them. Traffic to Nature’s Rainbows has experienced a major uptick, with folks going on to explore mineral lights, the Convoy article, and more (see the entry page table below for the past week).Referrals to Nature’s Rainbows have hit an all-time record high (see graph) of people searching for fluorescent mineral topics. Collecting fluorescent minerals, the Convoy UV flashlights, fluorescent mineral lights, were among the top blog posts on Nature’s Rainbows in the past. Visits per/day have doubled. New members in our FB group have skyrocketed.

This mania does exactly what the Fluorescent Mineral Society wants – spreads the word about our hobby. So – we say lighten up. Embrace it, don’t fight it. Have some fun, help new people learn, contribute to their understanding of fluorescent minerals. Make scientific posts, expand on collecting, guide new folks as they learn about our hobby. At the very least, stop complaining about all the Yooperlite posts. This will grow our hobby. 

For more musings on these glowing rocks visit : http://fredmhaynes.com/2019/01/15/fluorescent-sodalite-in-michigan/  

(From a paper written by ROGER H. MITCHELL AND R. GARTH PLATT, Department of Geology, Lakehead University, Thunder Bay, Ontario, Canada these rocks from the Caldwell Complex are nepheline syenite with minor and accessory pyroxene, biotite, natrolite, titanomagnetite, apatite, zeolite, fluorite, zircon, sphene and sodalite.)