Silica, 200 Mesh

Priced per pound.

Silica (SiO₂) is one of the cornerstone materials of glaze and claybody formulation. Although this mineral is present in many different ceramic materials (from feldspars to bentonite to sand, for example), this particular silica is the purified version. This version is 200 mesh size, which is typically used in slip and clay body recipes, while the finer 325 mesh is typically used in glaze recipes. Silica is known by a few different names in the ceramic industry, including flint and quartz. Some may debate the accuracy of these names -- particularly quartz -- but just know that if you hear either term, you are likely looking at a recipe that calls for silica.

As for silica's function in clay and glazes, it provides the melting, or glassifying agents in a claybody that allow the material to fuse together. Silica, however, has a fairly high melting point, so it does often need to be fluxed with the addition of other materials that spurn it to melt at lower temperatures. Silica imparts hardness to glazes, and decreases thermal expansion. In claybodies, the expansion factor is exactly the opposite -- an increased presence of silica increases the thermal expansion.

WARNING: This product can expose you to chemicals including Silica, crystalline (airborne particles of respirable size), which are known to the State of California to cause cancer. For more information go to www.P65Warnings.ca.gov.