These glaze cones are fired at cone 6 and have the same recipe: 20 Frit 3134, 21 EP Kaolin, 27 calcium carbonate, 32 silica. The difference: The one on the left uses dolomite instead of calcium carbonate. Notice how the MgO from the dolomite completely mattes the surface whereas the CaO from the calcium carbonate produces a brilliant gloss.
Dolomite matte glazes have the potential to be very silky and pleasant to the touch, while at the same time being hard, durable and non-crazed (if they are formulated correctly).
|Oxides||MgO - Magnesium Oxide, Magnesia|
|Oxides||CaO - Calcium Oxide, Calcia|