A modern model of an Aztec weapon called the Tepoztopilli thrusting spear.  This is only the spear head/tip, which could be attached to a main spear shaft of any size.  It measures around 9 inches long, with enough base for hafting if desired.  There are no known surviving examples that this author is aware of, and it is most clearly illustrated in the Spanish Codex Mendoza, written in 1541 after conquest.  It depicts this weapon used by Aztec warriors, and shows full length of spear from body height or a head taller than the warrior weilding it. (see picture above)   The wood base was made from Central American Bloodwood, and the obsidian blades were knapped here in traditional manner from a core, and then shaped to fit the grooved edge in order to follow the depictions available.  This model is made for display or teaching collections, but should still be considered dangerous and possibly deadly if handled by inexperienced students.   For this reason, the scalpel like edges on some of the blades have been touched by wetstone or pressure flakes, so that they do no have the microscopic razor blade scalpel edge, and are now sharp in the way most flaked arrowheads are, and do not immediately break the skin when touched.