Granular Manganese (60-80 mesh)Granular Manganese is manganese dioxide that has not been ground into a fine powder. Granular Manganese is used to create speckles in clay and glazes, which ilmenite and rutile can do but are not as effective as granular manganese. To achieve speckles in a cone 4 6 clay body using 60 80 mesh, 0. 2 0. 3% is used. However, the granular particles will begin to bloat and bleed into glazes at a cone 6. Information gathered from Digitalfire Ceramic