Cone 10 Reduction Nepheline Syenite 63.9 Dolomite 21.1 Zircopax 16.0 OM4 ball clay 4.3 ------------------------------ 105.3 Add: 1.0% red iron oxide 4.0% bentonite This usually comes out as a very attractive light yellow. It reacts with iron in the clay body, typically forming brown spots and streaks. The surface is matte