Silica, also known as flint or quartz. Also known as Sil-Co-Sil 90 (this appears on the bag as well) refers to the fact that the particle size is 90 microns, which can also be interpreted to 200 mesh. This version is most commonly used in clay bodies.
All ceramics are based on silica both in the body and glaze, except for a few specialized industrial products. It is the principal glass-forming oxide. Used as a white powder, it is derived from calcined and ground flints or ground quartz. - p. 252, Illustrated Dictionary of Practical Pottery, 3rdEd. by Robert Fournier
All ceramics are based on silica both in the body and glaze, except for a few specialized industrial products. It is the principal glass-forming oxide. Used as a white powder, it is derived from calcined and ground flints or ground quartz. - p. 252, Illustrated Dictionary of Practical Pottery, 3rdEd. by Robert Fournier
50# bag; brown bag, #90 printed on side
