06/20/2026
METEORITE VERSUS SLAG: Why Industrial Waste Is the World's Most Common Meteorwrong ☄️Slag Happens!
Over the years, we've produced hundreds of meteorite videos, interviews, presentations, and hangouts, but this may be one of the most important educational projects we've ever released. What began as a simple discussion about slag evolved into months of research, fact-checking, image collection, presentation design, and collaboration between meteorite experts, geologists, experienced collectors and our Knowledge Bolide Crew. The result is a comprehensive deep dive into one of the most common causes of meteorite misidentification and one of the most persistent sources of misinformation in the hobby.
We would also be remiss if we didn't acknowledge the tremendous contribution of our on-staff geologist, MIKE KELLY. His knowledge, insight, and willingness to share his expertise elevated this project far beyond anything we, Sue and Topher, could have accomplished on their own. Quite simply, this presentation would not exist in its current form without Mike's help, and we are incredibly grateful for the time and effort he invested in making it a reality.
If you've ever answered the "Did I find a meteorite?" question, purchased a meteorite online, worked with new collectors, or simply want to sharpen your own identification skills, this is a video you won't want to miss. We believe this presentation has the potential to help thousands of people avoid common mistakes, better understand the science behind meteorites and industrial waste, and become more informed members of the meteorite community. If you find the information valuable, please consider sharing the video with your clubs, groups, forums, social media pages, and fellow collectors. The more people we can reach, the fewer meteorwrongs will be mistaken for meteorites.
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Have you ever found a strange, heavy, magnetic rock and wondered, "DID I FIND A METEORITE?" If so, you're not alone. In fact, one of the most common answers meteorite hunters, geologists, museums, and meteorite dealers give to that question is, "NO, THAT'S SLAG."
In this special presentation, Topher, Sue, and on-staff geologist Mike Kelly take a deep dive into one of the most misunderstood subjects in meteorite identification: industrial waste, foundry waste, clinkers, smelting byproducts, and the many materials that collectors commonly lump together under the name "slag." This project took months of research and preparation and was inspired in large part by the work of renowned meteorite researcher Dr. Randy Korotev, whose educational resources have helped countless collectors avoid common meteorite identification mistakes.
You'll learn:
🔹 What slag actually is (and why the word is often used incorrectly)
🔹 The difference between slag, foundry waste, casting waste, clinkers, and other industrial byproducts
🔹 How iron production, copper smelting, steel manufacturing, welding, refining, and casting create materials that can fool even experienced collectors
🔹 Why magnetic attraction alone does NOT prove something is a meteorite
🔹 How bubbles, vesicles, glassy surfaces, metallic textures, and flow structures form in industrial waste
🔹 Why industrial waste can be found in deserts, forests, beaches, fields, railroad beds, construction sites, and places far away from factories
🔹 How slag has been reused for thousands of years in roads, railroads, shoreline stabilization projects, concrete, construction, and landscaping
🔹 Why some historic slags are now collected, displayed in museums, and even sold as art
Most importantly, you'll learn how to distinguish meteorites from meteorwrongs by comparing real meteorites and real industrial waste side-by-side.
Throughout the presentation, Mike Kelly explains the geological and metallurgical processes behind slag formation, including blast furnaces, steel production, casting operations, and the cooling processes that create the textures many people mistake for fusion crust. The team also explores how different cooling rates, chemical compositions, and manufacturing methods produce an incredible variety of industrial waste materials that often look surprisingly extraterrestrial.
The second half of the presentation focuses on actual meteorites and the features that separate them from industrial waste, including:
☄️ Fusion crust
☄️ Flow lines
☄️ Regmaglypts
☄️ Chondrules
☄️ Widmanstätten patterns
☄️ Metal distribution
☄️ Crystal growth structures
☄️ Internal textures visible in cut and etched specimens
Using numerous examples from witnessed falls, iron meteorites, ordinary chondrites, eucrites, mesosiderites, and other meteorite types, the crew demonstrates why proper identification requires looking at the complete picture—NOT JUST ONE FEATURE THAT APPEARS TO BE METEORITIC.
The presentation also includes an important safety discussion. Many industrial byproducts can contain heavy metals and other potentially hazardous materials. If you don't know what a specimen is, grinding, cutting, sanding, or inhaling dust from it can be risky. Proper handling procedures, protective equipment, and common-sense precautions are discussed throughout the program.
Finally, the crew highlights a growing problem in the collector marketplace: industrial waste being sold online as meteorites. Learn the warning signs, red flags, and common scams that can help protect both new and experienced collectors from spending thousands of dollars on something that never came from space.
Whether you're a seasoned meteorite collector, a rockhound, a treasure hunter, a detectorist, a prospector, or simply someone who has picked up a strange rock and wondered about its origin, this presentation will give you practical tools for separating genuine meteorites from one of the most common meteorwrongs on Earth.
Because sometimes... SLAG HAPPENS!
Have you ever found a strange, heavy, magnetic rock and wondered, *...
