Kyanite is a super-duty refractory material with very high resistance to thermal shock. It is widely employed in insulating brick, kiln furniture, refractory shapes, etc. and in body formulations used in porcelain, tile bodies, and casting mixes. The material reduces fired shrinkage, increases mechanical strength and thermal shock resistance and allows products to be made with thinner walls, better resistance to dunting, deformation and chipping. Kyanite's long jagged particles tend to form an interlocking no-shrink crystal matrix (like a felt) in bodies fired to low heat (potters use it up to 30% in raku bodies). Because of the particle shape, considerable amounts of kyanite can be added to bodies without adversely affecting their plasticity. For example, 10-15% 48 mesh kyanite can actually increase the plastic strength of smooth throwing bodies, making it possible to throw larger sized vessels. The above mentioned benefits will accrue and, in addition, drying properties will be better. However the dry and fired surface will been a little rougher. Its large grain sizes make an excellent high temperature grog. It is volume stable and has excellent hot load strength. Because of its expansion characteristics it makes an excellent crack filler