Talc Jetfil H290 - Various Sizes

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).