Roseville is a selectively mined stoneware clay this is exceptionally clean [and has less sulfur than goldart] and when ordered in 200 mesh offers the potter a stoneware fireclay which works well by itself or in compound bodies. The fired color is warm buff and it has a firing range of cone 1 to 8. This material will respond to deflocculants and can thus be used in slip casting bodies. This has been used for over 100 years by Roseville and Zanesville, OH potters. Some add small amounts of grog to impart texture and improve drying. - Digital Fire ceramic materials database