The Olmecs are known as “rubber people,” a name given to the peoples of the Gulf Coast after the Spanish Conquest. We don’t know what they called themselves.
Items buried in offerings included ceramic vessels, stone sculptures, obsidian blades, seashells, greenstone, and objects gathered from earlier locales (like Olmec sites and the city of Teotihuacan). Jadeite was quarried in the Sierra de las Minas in Guatemala, and was imported to the Gulf Coast of Mexico. Items acquired via trade or tribute (by the Aztecs) included feathers, obsidian, jadeite, cotton, cacao, and turquoise.