Pumice FAQs

I’m thinking pumice...can you help me determine if pumice would work for my particular needs?

Absolutely. For over 50 years, we’ve been mining, refining and supplying pumice products to industry. We know our stuff. Pumice is amazingly versatile, but if it turns out that our pumice powders, sands, or aggregates aren’t the best solution for you, we’ll tell you what is.

What is pumice used for?

Pumice is used widely in industrial processes and consumer products. We've a comprehensive listing of pumice uses on the Uses for Pumice page.

What grades of pumice powder do you make?

We process over 300 grades of pumice...from one-inch mine-grade aggregate down to super-fine powders of 3 microns (equivalent to smoke), used in our cementitious ultrafine grout product. A table of our standard (stocked) grades is available on the pumice grades and types page.

Sure, Hess refines a lot of pumice grades, but what if I need something special?

If we don’t currently produce a grade (we produce over 300 spec grades) that meets your specifications, we will work with you to develop one. Call or email our sales manager. He’ll make sure you get what you need, packaged to fit your requirements, shipped to wherever you need it, worldwide.

How soon can I get pumice?

Production turnaround time for most grades is two (2) weeks to be ready for shipment. We also have stocking distributors located worldwide that may be able get you product more quickly.

I’d like to run some tests at my lab. Can I get samples?

Were happy to get you what you need. Contact Brian Jeppsen, VP Research and Development, at (208) 766-4777 x111 or email rd@hesspumice.com to discuss your needs and request a sample of the brightest and hardest amorphous aluminum silica (pumice) commercially available in the world.

Where can I buy small amounts of pumice for personal use?

You can order pumice online from our pumicestore.com for a variety of uses. Available in a 1 pound bag to a 20 pound box (or multiples).

Do I buy pumice directly from Hess Pumice or from a distributor?

We have a network of Domestic and International Distributors. Call 1-800-767-4701 x 147, and we’ll connect you with the most appropriate distributor representative.

In some cases, based on volume and/or location, direct purchasing arrangements can be established.

What are my shipping options?

Hess ships pumice worldwide via rail, truck, intermodal and overseas via ocean carrier in canisters as small as 2 grams to bulk rail cars holding 100 tons. We ship to any continent. Wherever you are, we’ll get it there.

We know your supply chain is crucial—that product must arrive on spec, on time, and packaged conveniently for end use. We’re serious about remaining the most sophisticated producer and supplier of pumice in the world market. And quite honestly, we’re very good at it.

Pumice is pumice, right? It’s all basically the same.

No. Pumice is not created equally by nature. The color, the hardness, the purity, the chemical composition of the pumice—it all differs from deposit to deposit. Nor are the companies who supply pumice commercially equal in their ability to refine pumice to any needed grade and do so consistently. Hess processes pumice in three state-of-the-art plants sourced from a superior pumice deposit that is in demand around the world.

So...what is pumice, exactly?

Amorphous aluminum silicate originating as volcanic ash. We've dedicated a page to this question: The Story of Pumice.

In short: A foam of volcanic glass—silky, interlocking fibers filled with tiny air bubbles. It is these frothy vesicles that give pumice its unique and infinitely useful qualities. Pumice has no crystalline structure, is naturally calcined, and is abundant, economical, and sustainable.

Does pumice color matter?

In certain industrial applications, it certainly does. Take, for instance, the decorative concrete industry. Pumice is used as both a lightweight aggregate and a concrete performance super-charging pozzolan. But it’s the whiteness of Hess pumice—scoring a GE brightness of 84—that seals the deal: as the final whiteness of the concrete product or the pureness of its dyed color is critical. Manufactured stone veneer products (pumice is used as a lightweight aggregate) and Glass Fiber Reinforced Concrete (GFRC) structure cladding panels (pumice pozzolan adds strength and density) are two examples of such products.

What about the purity of your pumice?

We employ specialized impurity extraction technologies which make it possible to achieve an extremely high purity content for our pumice—98% - 99.8%, depending on grade.

Nearly 70% of our pumice products are shipped to markets outside of North America due to advantages in purity and color.

Where can I find data sheets, safety information and other official documents?

We have an extensive Downloads Library where you can view informational PDF files, including Safety Data Sheets, Technical Data Sheets, Certifications, Statements and Declarations, Knowlege Briefs and more.

Pumice bagging equipmentPumice bagging equipment.

We have stocking pumice product distributors in 23 countries on six continents.

“Pumice” and “Pozzolan”...the same thing?

Anciently, yes. Pozzolan, or as the Romans called it, Pozzolana, is a finely ground pumice, which, when mixed with their hydrated lime cement, resulted in an incredibly durable concrete. Today, there are other concrete additives used as “pozzolans,” typically fly ash (a byproduct of the coal-fired power industry), silica fume (byproduct of producing silicon metal or ferrosilicon alloys), metakaolin (a calcined kaolin clay), and others. But pumice is the original, natural pozzolan. Hess UltraPozz was chosen over all other pozzolan products (above) by the U.S. Department of Energy and Canadian Atomic Energy Commission scientists in developing the cementitious permeation grout needed to seal microfractures in the confinement caverns deep underground at the DOE’s Waste Isolation Pilot Plant in New Mexico.

Is pumice safe to work with?

Being chemically inert and crystalline silica-free, Hess Pumice is both safe to use and safe for the environment.

Do you supply large pumice stones?

No. The largest available is a mine-grade aggregate averaging one inch.


We know pumice. Well be glad to answer your questions, join you in your lab for tests, or simply supply a sample for testing—whatever you need.

SALES: If you need to talk availability, grades or grade blends, logistics, costs...contact Jason Kimberling, Sales Manager, at extension 142 or email salesmgr@hesspumice.com

•RESEARCH: Perhaps you are exploring the possibilities—thinking pumice may fit your particular need, thinking you’d like to run some tests with our pumice—then we invite you to contact Brian Jeppsen, VP Research and Development, at (208) 766-4777 x111 or email: rd@hesspumice.com


208.766-4777  •  Malad City, Idaho 83252