One thing you have to keep in mind about meerschaum is the name on the pipe, if it has one, has
nothing to do with it's "manufactured" quality. Meerschaum isn't 'made' by the distributor. It's
mined by someone, carved by another and sold to the guy that puts his name on it. In some cases
the carver's name goes on it and he may sell it himself if he's the master carver.
Also the quality of the mineral comes in play. Some have better absorption qualities than others,
depending on where the stone was mined and how deep.
As sblumberjack said, some are made of powder that's swept up off the carving room floor and pressed
with glue to make cheep pipes. (Most calabash bowls are of this variety). Block Meerschaum is the
only way to go as far as I'm concerned.
The one quick way to tell is... wet the bowl and see if it's absorbed or stays there. (I wouldn't
use saliva if's it's not my pipe). If 'the wetness' is immediately absorbed, it's block meerschaum.