We are the only ones out there that are offering such a selection of these beautiful pieces. We do not clean them..So, sometimes you see them dusty, dark, brown, ...Please keep that in mind. We've sold a lot of these to museums that do chocolate demonstrations. Also, we've sold these to the Smithsonian in D.C. as well as the preferred supplier the Hershey Company. A good washing with warm water will do the trick. These are grinders, usually for corn that were used in the old days. They are made out of lava rock,(heavy) the same material as the "molcajetes"(pestle & mortar). This Antique metate measures about 12.5x18.5x11 in. This mano (hand) measures about 2.5X10 inches. The design on most of these old metates, incorporates three legs, with the back one usually being taller, to aid in the grinding process. Imagine that this is one piece. The top part and the three legs are all hand-carved out of a big chunk of lava rock. Please understand that these are old and will sometimes,