US Patent 8162247 Grinding system

A grinding system includes a mortar container having an open top portion and a bottom portion having a first interior grinding surface and a wall portion interconnecting the top and bottom portions for defining a hollow interior collection chamber, a modular pestle assembly including a universal pestle shaft having at its proximate end an actuator portion extending above the top portion and at its distal end a mounting portion for receiving one of a set of pairs of matching tips and pestle collars, the pestle tip having a second grinding surface for engaging the first grinding surface, and a closure device sealingly engageable with the pestle assembly and the open top portion for sealing the container and the collection chamber between the grinding surfaces and the top portion of the mortar container.