Talc vs dolomite powder
Talc (Mg3Si4O10(OH)2) and dolomite (CaMg(CO3)2) are both soft mineral fillers but solve different problems. Compare composition, hardness, chemistry and the applications where each wins.
Both are soft, white mineral fillers from the same region, so buyers often confuse them. The choice is decided by what you need the filler to do — stiffness and heat resistance point to talc; combined CaO + MgO or a lower price points to dolomite.
Composition at a glance
Talc is hydrous magnesium silicate (Mg3Si4O10(OH)2), Mohs hardness 1, lamellar. Dolomite is calcium magnesium carbonate (CaMg(CO3)2), and our standard runs CaO 27–35%, MgO 22–30%, whiteness 80–95%. Talc is the softer, more plate-like of the two.
For a quick check: if the specification calls for both calcium and magnesium in one material, dolomite is the natural fit; if it calls for stiffness and low equipment wear, talc is.
Where each wins
Choose talc for plastics and masterbatch where stiffness, heat deflection and low abrasion on screws/rolls matter, and in coatings for matting and sanding. Choose dolomite for glass and ceramics (both fluxes in one feedstock), construction mortar and flue gas desulphurisation where the CaO + MgO combination and cost matter more.
If whiteness above 90% is required, talc grades reach 87–93% and our GCC reaches 97%; dolomite tops out around 95%.
How we help you decide
Send your application and any existing specification; we will propose talc, dolomite or a blend, with TDS and free samples, rather than leaving you to guess from a catalogue.
For calcium-carbonate options, see our separate GCC vs PCC comparison.
Related applications
Need a custom specification?
Tell us your target mesh size, whiteness and application. We send samples and a quotation within 24 hours.