Polar Ice (Plainsman Clays) has been fired to cone 10R (left). This is beyond the recommended cone 6 range, but it worked well in this instance. The result is even more translucency and a translucency of a different character: blue! This looks much more like real blue polar ice.
A highly sought after property in porcelain, they are fired close enough to melting to pass considerable light. It can be very difficult to fire translucent ware without it warping.
A method of firing stoneware where the kiln air intakes and burners are set to restrict or eliminate oxygen in the kiln such that metallic oxides convert to their reduced metallic state.