You’ve probably seen it in the bottom of a potting mix bag—those little gold-colored, accordion-looking nuggets that feel like a mix between a rock and a sponge. Or maybe you're staring at a pile of gray insulation in your attic and feeling a sudden surge of anxiety.
Finding out who vermiculite made by is actually more complicated than just looking at a brand name on a bag at Home Depot. Because vermiculite isn't "made" in a factory like a plastic widget. It's a natural mineral, a hydrated magnesium-aluminum-iron silicate, that’s pulled out of the ground.
But who owns the ground? And who turns that raw ore into the fluffy stuff we actually use?
The landscape of the vermiculite industry has changed wildly over the last few decades. If you’re looking for the short answer: a handful of global mining giants like Palabora Mining Company and Dicalite Management Group dominate the market today. But the backstory? Honestly, it’s a bit of a rollercoaster involving corporate collapses, massive lawsuits, and a tiny town in Montana that changed everything.
The Big Players Mining the Earth Right Now
If you buy a bag of vermiculite in 2026, there’s a massive chance it originated from one of three places: South Africa, the United States, or Brazil.
The undisputed heavyweight champion of the world is the Palabora Mining Company (PMC). Located in the Limpopo Province of South Africa, this operation is a beast. They churn out over 180,000 tons of the stuff annually. If you’re a professional grower or an industrial manufacturer, your supply is likely coming from here. Why? Because Palabora vermiculite is famous for being "clean"—meaning it doesn’t have the nasty asbestos contamination issues that plagued the industry in the past.
In the United States, the scene is much smaller but still vital. There are basically two main spots where the raw ore is pulled from the earth:
- Virginia Vermiculite LLC: These folks run a private operation in Louisa, Virginia. They’ve been at it since the mid-80s and are one of the last standing commercial producers in the States.
- Specialty Vermiculite (Dicalite Management Group): Operating out of Enoree, South Carolina, this company handles everything from the initial mining to the thermal expansion process.
You also have Imerys, a French multinational that is essentially the "everything" company of industrial minerals. They own the Shawa mine in Zimbabwe through their subsidiary, Samrec. They’ve been ramping up production recently to meet the crazy demand from the construction and horticulture sectors.
Wait, What About the Stuff in My Attic?
This is where the "who made it" question gets tense. If you are asking because you found old insulation in your house, you aren't looking for a modern mining company. You’re likely looking for W.R. Grace & Co.
For the better part of the 20th century, W.R. Grace owned a mine in Libby, Montana. That single mine supplied about 80% of the world’s vermiculite. They sold it under the brand name Zonolite.
The problem? The Libby mine had a massive natural deposit of tremolite-actinolite asbestos running right through it.
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When W.R. Grace processed the vermiculite, the asbestos came along for the ride. Millions of homes were filled with Zonolite insulation that was secretly laced with toxic fibers. The company eventually faced over 129,000 lawsuits, leading to one of the longest bankruptcies in U.S. history. Today, the Libby mine is a Superfund site, and W.R. Grace (now owned by Standard Industries) mostly makes specialty chemicals, staying far away from the vermiculite mining business.
The "Popping" Process: Who Actually Makes the Fluff?
There is a big difference between the mining company and the expander.
Raw vermiculite ore looks like flat, heavy mica flakes. It’s useless in that state. To get the lightweight material we know, it has to be "exfoliated." This is basically like making popcorn. You heat the flakes to about 900°C (1650°F), the water inside turns to steam, and the flake blows up into a long, worm-like shape.
Many companies buy the raw "concentrate" from the big mines and do the popping themselves. Some names you might run into include:
- The Schundler Company: A family-run business in New Jersey that’s been expanding minerals since 1951. They are basically the encyclopedias of the industry.
- Whittemore Company: Based in Massachusetts, they specialize in custom blends for construction and "pool base"—that soft layer under vinyl pool liners.
- Therm-O-Rock: They have plants in places like Pennsylvania and Arizona, serving as regional hubs for expanded product.
Why the Manufacturer Matters for Your Garden (or House)
You might think vermiculite is just vermiculite. Not quite.
The quality depends on the "grade" or particle size. Palabora and Virginia Vermiculite produce different grades ranging from "Superfine" (which looks like sand) to "Large" (which looks like small croutons).
If you're a gardener, you want the coarse stuff for aeration. If you're a brake pad manufacturer (yeah, vermiculite is in your car’s brakes), you need the micron-sized powder.
There's also the "yield" issue. Lower-quality ore doesn't expand as well, meaning you get more "sinkers" (unexpanded rock) in your bag. High-end companies like Dicalite use sophisticated flotation circuits to make sure you’re getting pure, expanded mineral rather than a bag of heavy rocks.
How to Check Who Made Your Specific Bag
Honestly? It's hard.
Most consumer-facing brands—the ones you see in the garden center—are "white labeled." This means a company like Miracle-Gro or a local nursery buys bulk expanded vermiculite from a processor like Schundler or Whittemore, who in turn bought the ore from Palabora or Virginia Vermiculite.
If you really need to know the source for safety or technical reasons, look for the SDS (Safety Data Sheet). Every bag should have one available online from the distributor. It will list the manufacturer of record and often mention the origin of the ore to prove it’s asbestos-free.
Actionable Next Steps
- If you have old attic insulation: Do not touch it. Period. If it looks like pebbles or accordions and was installed before 1990, assume it is Zonolite from the Libby mine. Contact a certified asbestos professional for testing.
- If you are a gardener: Look for "professional grade" bags. These often come from reputable expanders like Dicalite or Whittemore and have fewer "fines" (dust), which can actually suffocate plant roots rather than help them.
- If you are buying in bulk: Request the Certificate of Analysis (COA). Any modern, reputable supplier (like those mentioned above) will provide documentation proving their product is tested and "non-detect" for asbestos fibers.
- Check for the "Zonolite Trust": If you do find W.R. Grace insulation in your home, you might be eligible for reimbursement for removal costs through the Zonolite Attic Insulation Trust. It’s a tedious process, but it can save you thousands.
The vermiculite industry is cleaner and more transparent than it’s ever been, but knowing the "who" behind the "what" is the only way to stay safe and get the best results for your project.