Steatite soapstone is mined in many places around the world. For all the deposits mined in Canada, I have to buy soapstone from Brazil.
Kudlik = Quilluq come in many sizes from, maybe 6" x 8" x 1" deep to cooking/heater seal blubber ones with 24" of fire along one edge.
I haven't settled on the sizes to carve from the stone I just bought.
Inuit in Canada are working a lot of serpentine in every major art & carving center in Nunavut and the Northwest Territory.
I see them using the size that Janne suggests up to maybe 15 x 15 x 30cm. Transportation south is the killer.