The Aztec Macuahuitl
1300–1521 CE
The macuahuitl was an Aztec wooden sword embedded with rows of obsidian blades that Spanish conquistadors described as capable of decapitating a horse with a single blow. Obsidian is 3 times sharper than surgical steel — it can be knapped to an edge just one molecule thick. The macuahuitl combined the cutting power of obsidian with the impact force of a club, creating a weapon that was arguably more lethal than a steel sword in close combat.