Iron was never smelted by Native Americans, thus the New World never entered a proper "Iron Age" before European discovery, and the term is not used of the Americas. But there was limited use of native (unsmelted) iron ore, from magnetite, iron pyrite and ilmenite (iron–titanium), especially in the Andes (Chavin and Moche cultures) and Mesoamerica, after 900 BCE and until . Various forms of iron ore were mined,
drilled and highly polished. There is considerable evidence that this technology, its raw materials and end products were widely traded in Mesoamerica throughout the Formative era (2000–200BCE).
Lumps of iron pyrite, magnetite, and other materials were mostly shaped into mirrors, pendants, medallions, and headdress ornaments for decorative and ceremonial effect.
However, concave iron ore mirrors were apparently used for firing and optical purposes by the Olmec (1500–400BCE) and Chavin (900–300BCE) cultures,
and ilmenite "beads" may have served as hammers for fine work.
The Olmec and Izapa (300BCE – 100CE) also seem to have used iron magnetism to align and position monuments.
They may have developed a zeroth-order compass using a magnetite bar.
Some Mesoamerican uses of native iron seem to have been military. Steven Jones proposed that the Olmec sewed ilmenite "beads" into protective mail armour or helmets. Iron pyrite mosaics and plates formed protective tezcacuitlapalli (mirrored back flap shields) and breastplate ornaments in the military attire of the Teotihuacan (100 BCE – 600 CE), Toltec (800–1150 CE) and Chichen Itza (800–1200 CE) cultures.