Diatomaceous earth (DE) is one of those words that sounds like a chemistry warning and is actually a fossil. This guide explains what diatomaceous earth is, why it's the most absorbent natural material on the kitchen counter, what we asked the Orange County Cooperative Extension office about its safety, and how to keep your stone mat from cracking when you drop a glass on it.

What diatomaceous earth actually is

Diatomaceous earth is the fossilized skeletons of microscopic algae called diatoms. These algae built shells out of silica. When they died (millions of years ago), the shells settled into chalky white deposits. Mined, milled, and pressed into mats, blocks, and trays, the result is a material that's roughly 88-92% silica — and incredibly porous at the microscopic level.

What you see when you look at a diatomite mat under a microscope: a honeycomb of tiny tubes. That's the absorption mechanism. Water doesn't sit on the surface; it gets pulled into the structure and evaporates from inside.

Why it dries dishes faster than microfiber

A microfiber towel holds water in the fibers. A diatomite mat pulls water through the surface and into the body of the stone, where it evaporates from a much larger surface area than a flat towel. Result: a wet bowl placed on diatomite is dry in 8-15 minutes. The same bowl on a microfiber towel takes 25-40 minutes and the towel itself is now wet.

Practical consequence: no sour-towel smell, no daily laundry, no wet rag on the counter.

Is it safe in kitchens?

Yes — for kitchen-grade product. Two important distinctions to understand before you buy:

• Food-grade diatomaceous earth (the powder used in agriculture and as an anti-caking agent in stored grain) is regulated by the EPA and FDA and is safe for human contact and incidental ingestion. Our mats and trays are made from a related material — kitchen-grade diatomite — which is the same source material pressed into a solid form.
• Industrial-grade DE (used in pool filters) is heat-treated to crystalline silica, which has different lung-exposure considerations and is not what's used in kitchenware. If a kitchen mat is labeled "diatomaceous earth," it should not contain crystalline silica. Reputable brands publish material data sheets.

We confirmed the kitchen-grade safety question with the UC Cooperative Extension office in Orange County — their consumer-information desk handles these questions for residents and farmers alike. Their position: kitchen-grade pressed diatomite is safe for food contact and is not the same exposure profile as airborne crystalline silica from industrial use. If you want to dig deeper, they're a free public resource — search "UC Cooperative Extension Orange County" and call the master gardener helpline.

Care: keeping a stone mat from cracking and staining

Two things kill diatomite mats: drops and stains. Both are preventable.

1. Don't drop it. Diatomite is porous, which means it's also brittle. A 2-foot drop onto tile cracks it. Move it like a ceramic plate, not a silicone mat.
2. Sand off stains. Coffee, tea, tomato sauce — they soak in. The fix: 600-grit sandpaper, light pressure, sand the stain out, wipe with damp cloth, air dry. The mat looks new again. Do this every 6-8 weeks.
3. Re-pore weekly. Soap residue clogs the pores. Once a week, scrub with a soft-bristle brush and warm water (no soap), then air-dry standing up.
4. Don't put it in the dishwasher. Heat shock will crack it.

Full routine: Diatomite care guide.

Diatomite vs silicone vs microfiber

• Diatomite: Fastest dry time. Looks the cleanest. Cracks if dropped. Sandable when stained. Best for daily-use kitchens with countertop discipline.
• Silicone: Indestructible. Dries dishes by gravity (water rolls off, slow evaporation). Yellows over time. Best for households with kids who throw glassware.
• Microfiber: Cheap. Holds smells. Daily laundry. Best as a backup, not a primary.

Our diatomite line

• Full diatomite collection — mats, sink trays, soap holders

Questions about diatomite safety or care? Email me — lisa@strabella.org. — Lisa