The obsidian monkey is one of the most attractive pieces in the Mexica Hall. Its design and finish make it an exceptional object. It is a vessel made of well polished obsidian. Upon observing the surface finish one must take into account the equipment that Mesoamerican groups had. This piece was made with different lithic-work techniques of such as percussion, pressure and, finally, polishing with the use of very fine sand and water, most likely. Mtro. Hugo García Capistrán