know what this is?
 

Hey just curious if anyone knows about this..... weighs about 150 pounds
Solid marble polished on the inside rough outside.
Been searching around, not much luck. My dad got it when he was cleaning out a basement of an elderly fellow about 40 years ago.
Someone said it could be a 'mochi pounder' ???

bigger pictures here: Pictures by chucksiron - Photobucket


Thanks
Charles

Looks like a Mochi Pounder.

The mortar looks unusually small for pounding mochi, compared to the size of the mallet.