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Glaze material · Fluxes, feldspars & frits

Dolomite

Also sold as: calcium magnesium carbonate

Calcium and magnesium flux in one mineral, active at high temperature.

fluxContributes: CaO · MgO

In published recipes

Used in 2,402 of 10,859 glaze recipes (22%)

Typical amount when present

10% of the dry batch — half of recipes fall between 6% and 17%.

Fired surface of those recipes

Glossy 50% · Matte 21% · Semi-glossy 17% · Satin 12%

Cones where it appears

Share of recipes containing this material that fire to each cone.

Most often mixed with

Materials that appear in the same recipes most often.

Chemistry

Raw formula
CaCO3·MgCO3
Molecular weight
184
Fired formula
CaO·MgO
Equivalent weight
184

From Linda Arbuckle's materials table. Mineral formulas are idealized; buy an analysis for the bag you have. Equivalent weight is the weight that supplies one molecule of the fired oxide — the number glaze calculation uses.

What potters should know

Gives the soft, buttery mattes and pastel colours that magnesium is known for, and purples with cobalt.

Handling and safety

Dry ceramic materials generate respirable silica dust. Use a NIOSH-approved N95 or P100 respirator and adequate ventilation when mixing dry, and wet-clean surfaces.

This information is provided for planning purposes and is derived from publicly available sources including OSHA regulations, NIOSH guidance, and manufacturer safety data sheets. It does not constitute professional safety advice. Consult your material suppliers' SDS documents and applicable local regulations for authoritative safety guidance.

Questions

How much Dolomite do potters use in a glaze?
Across 2,402 published glaze recipes containing it, the typical amount is 10% of the dry batch, with half of recipes between 6% and 17%. Colorants and additives sit far lower than fluxes and glass formers; treat these as a range to test around, not a target.
What cone is Dolomite used at?
It appears in recipes across the range; the most common cones among published recipes are cone 6, cone 10, cone 9. Where a material sits depends on the rest of the recipe more than on the material itself.
Is Dolomite safe to use?
It carries no specific hazard flag beyond the general rule for all dry ceramic materials: avoid breathing the dust and read the supplier's SDS.

Related materials

Glaze materialrecipestypical
Whiting5,46212.5%
Magnesium carbonate3845.5%
Talc1,9758.1%

Sources. Usage figures are computed by Claybench over 10,859 glaze recipes compiled from publicly shared community recipe collections (snapshot 2026-02-27) — counts only; no recipe is reproduced, and the figures describe that collection, not every recipe in existence. Material roles and notes are paraphrased from Linda Arbuckle's Ceramic Materials handout unless noted. Hazard notes summarise supplier SDS guidance; read the SDS for the product you buy.

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