African Meerschaum is usualy not pearl white but has a more brownish/ cream colour and is in some cases even pitch black, though I dont know if this is how it natural occurs or if it is colored in some way, as appearently there is/was a method of cooking the meerschaum in tar. It is also usualy a little heavier then the turkish variant but quality wise, I would say both are good. I have about 4 African and 5 turkish meers and both get smoked with the same regularity. As far as I know, Petersons Meerschaum Pipes should be mostly african meer especialy anything made after the 1960s when the export embargo from turkey kicked in.
