gems, jade, jadeite, fei cui, Mesoamerica, Mexico, Guatemala, Costa Rica, Mayans, Olmecs, Aztecs, archaeology, history, archaeogemology, Pre-Columbian jade; Costa Rica; Maya; exchange; iconography, lapidary, agate, onyx, quartz, chalcedony

In making vessels from stone, the ancient Mexicans attained a high degree of proficiency, judging from the few specimens that have been preserved in museums and private collections. The most remarkable are those made from obsidian and onyx. Some of the finest examples are housed in the National Museum in Mexico City. These vessels are sometimes plain, unadorned cups, but more often incorporate representations of animals, with the head and limbs projecting from the body of the vessel. One notable example in the museum is carved from brilliantly polished obsidian and depicts a crouching monkey, its arms hanging from a hoop carved around the rim. The same museum also possesses an unfinished vessel carved from onyx. Hollowed out but not yet polished, it represents an animal similar to that depicted on the example described and illustrated from the present collection. Such vessels were carved from a single solid block of stone, leaving walls of varying thickness, averaging about 5 mm around the sides. In most cases they are finely finished and highly polished.