Middle and South Europe, grog is used to create fire-resistant chamotte type bricks and mortar for construction of fireplaces, old-style and industrial furnaces, and as component of high temperature application sealants and adhesives. A typical example of domestic use is a pizza stone made from chamotte. Because the stone can absorb heat, you can bake pizza or bread on the stone in a regular domestic oven. The advantage is supposed to be a more even heat. A normal commercial domestic oven cools down when the door is opened. The stone however remains hot, creating a more even bake. Another advantage is the fact that the stone can absorb some moisture making for a drier bake. Archaeology In archaeology, "grog" is crushed fired pottery of any type that is added as a temper to unfired clay. Several pottery types from the European Bronze Age are typologized on the basis of their grog inclusions. The practice of adding grog to clay as a temper was widespread throughout many cultures, and is mentioned in the writings of Hai Gaon (939–1038), who wrote in his commentary on the Mishnah, compiled in 189 CE: "ḥarsit [= grog], that which they grind [of potsherds] and make therewith clay is called [in Hebrew] ḥarsit." See also Grogg References . . External links What is Grog in Pottery? Ceramic materials Refractory materials Silicates