A useful anti-craze constituent of cone 06-04 clay bodies owing to the formation of high contraction enstatite crystals. Also an effective anti-craze glaze ingredient when substituted for wollastonite (keeping talc to <13% of the recipe) due to reduced glaze contraction. High-talc, magnesian matt glazes are noted for a purple colour response from cobalt.
Note: Dark Grey Amtal Texas Talc is no longer being mined. New Magris Jetfil H 290 talc is its substitute. Glazes calling for a lot of talc might need adjusting to restore the oxide balance. To do that, for every 100 g of Amtal talc in the recipe, add 100 g Magris talc +15 g silica + 9 g wollastonite and remove 20 g kaolin (or clay).
For more information on talc, see the Digitalfire.com Reference Library of ceramic materials.Different Raw Materials ordered in full bag qty (20 kg to 100 lb) will be combined at checkout for a volume discount if applicable.