Cornwall Stone Substitute Stoneware Opal Glazes USG Hydrocal® White Gypsum Cement

USG Hydrocal® White Gypsum Cement is especially suitable in thin

there is no gain in drying properties (the most common reason for adding grog to clay bodies)

Smooth talc free clay that fires light red

Sets 25-35 minutes after machine mixing

Cornwall Stone Substitute Stoneware Opal Glazes USG Hydrocal® White Gypsum CementThe original Cornwall Stone Mine is now closed, and this material is now produced synthetically by Laguna Clay Co. Because it was mined from granite rock (traditionally, from the Cornwall area, UK), it is actually composed of a combination of minerals, and the ratio of these chemicals could vary somewhat drastically. This means that potters who used this material over long periods may notice different results when using the same recipes. An advantage