Grill Mark · Pizza Stones & Baking Surfaces
Grill Mark Corderite Stone Grill Pizza Stone 13 in. L X 13 in. W 1 pk
Lower-concern choice; cordierite stone has no known PFAS risk.
Cordierite pizza stones are uncoated mineral products with no nonstick or water-repellent finishes where PFAS typically appear. The brand makes no PFAS claims, but the material itself poses minimal concern.
The better-graded swap
15-Inch Ceramic Pizza Stone for Perfect Crispy Crusts
90/100 safety
Same rubric that flunked this product. The swap earned Excellent.
Still want this one anyway? Check the price on Amazon. We’d swap it.
Material
Cordierite stone (mineral-based ceramic)
Brand disclosure
Brand is silent on PFAS
Lab data
No public lab test
What’s concerning
Category baseline
The starting point for this type of product, before anything specific to this product is counted.
No PFAS disclosure
No public statement from the brand about PFAS in this product.
Thermal shock and fracture risk
Cordierite is more resistant to thermal shock than some ceramics, but rapid temperature changes (cold water on hot stone, moving directly from cool to very hot oven) can still cause cracking. Once fractured, sharp edges and structural failure create both burn and handling hazards.
Microcracking and gradual dust generation
Over years of use, cordierite stones can develop fine surface cracks from repeated heating cycles, potentially shedding microscopic ceramic particles. This is a minor concern for food contact but not documented as a significant health risk in established literature.
What’s reassuring
Base material not linked to PFAS
The main material recorded for this product is not one associated with PFAS.
Lead
Grill Mark cordierite stone is unglazed and uncoated, eliminating this hazard entirely. Fired cordierite mineral itself does not leach heavy metals under normal cooking conditions.
Source, ATSDR ↗Contamination from manufacturing residue or mineral impurities
Cordierite is a well-defined mineral compound with few toxic naturally occurring impurities. No published recalls or testing results indicate heavy metal or radioactive contamination in this brand's cordierite stones.
Off-gassing or volatile organic compounds (VOCs)
Fired mineral ceramics like cordierite do not off-gas VOCs in the way that synthetic polymers or heavily treated wood products do. No chemical treatments, adhesives, or sealants are present in this unglazed stone.
The full breakdown
What it's made of and why it matters
Cordierite is a naturally occurring magnesium-aluminum silicate mineral prized for pizza stones because it resists thermal shock and doesn't require seasoning like cast iron. Granite Ware's Grill Mark stone is a fired ceramic product with no glaze or enamel coating, meaning no lead or cadmium leaching risk from surface treatments. The porous cordierite body absorbs and distributes heat evenly, mimicking traditional brick ovens. At 1 inch thickness, it's durable enough for repeated oven and grill use without cracking under normal temperature cycling.
The brand's record and disclosure
Granite Ware (a division of Regal Ware) does not publicly disclose PFAS testing or manufacturing certifications for this specific product line. The brand has no documented safety recalls tied to cordierite pizza stones. No third-party certifications (NSF, CPSC, or material-specific) are marketed for this model, which is typical for basic ceramic baking surfaces in this price tier. The company's silent stance on PFAS and chemical transparency is unremarkable but not reassuring.
How it compares in its category
Cordierite pizza stones are a middle ground between cheap ceramic tiles (which may have unknown glazes) and premium branded stones with marketing claims. This Grill Mark model competes with similar unglazed cordierite products from Lodge, Emile Henry, and store brands. Unlike some budget alternatives, cordierite's natural composition avoids synthetic coatings and chemical stabilizers. Price and durability are on par with competitors; differentiation is minimal for a utilitarian thermal ceramic.
If you buy it
Preheat the stone gradually in a cool oven, raising temperature by 100F every 15 minutes to avoid thermal shock cracking. Do not immerse in water or use soap; wipe with a damp cloth after cooling completely. Maximum safe temperature is typically 500F for home ovens (check your appliance manual). Replace if you notice deep cracks that go through the thickness, as these can lead to sudden breakage. Dust flour or cornmeal off between uses to prevent buildup that can burn or smoke.
What we don’t know
- Basis
- Model estimate, 85% confidence, not a lab result
- Lab test
- None on record for this exact product
- Brand statement
- Grill Mark has made none
Formulations change between production runs, so check the current label. How we grade.
Better-graded alternatives in Pizza Stones & Baking Surfaces
15-Inch Ceramic Pizza Stone for Perfect Crispy Crusts
Ceramic (clay-based baking stone)
Glaze degradation and surface leaching
Limited concern
Thermal stress fracture
High concern
Microporosity and microbial retention
Limited concern
Brand PFAS statement on record, which we have not verified.
⚠Starting grade for this product type
Deluxe Square Pizza Stone with Rack
ceramic or unglazed stone; no nonstick coating
Ceramic or stone cracking and fragmentation
Limited concern
Porous surface harboring bacterial or mold growth
Limited concern
Brand PFAS statement on record, which we have not verified.
⚠Starting grade for this product type
Baking Steel
The Original Ultra Conductive Pizza Stone
carbon steel (bare metal, no coating)
Rust and corrosion
Limited concern
Thermal safety and burns
Moderate concern
Lower concern; bare carbon steel has no PFAS-prone coatings.
⚠Starting grade for this product type
More pizza stones & baking surfaces grades
How we score, every product runs through the same public 0-100 rubric based on materials, coatings, brand disclosure, lab findings, and recalls. See the full methodology → Spotted a mistake? Report an error.