1.4" Etched Toluca Iron Meteorite (16.6 g) Slice - Mexico

The Toluca Meteorite

The Toluca meteorite is a coarse octahedrite (Iron, IAB-sLL) meteorite, one of the oldest known meteorites on Earth. It fell in south-central Mexico as early as 50 to 60,000 years ago near the present-day city of Toluca. It was likely used by local peoples to craft tools and weapons, and was recognized as a meteorite by the West in 1776. Its main mass is held in Mexico City.

When etched, this meteorite displays wonderful, interlocking Widmanstätten lines. It can also contain dark nodules of silica in places.

About Iron Meteorites

Iron type meteorites are composed primarily of iron and nickel, and are the remnants of differential cores torn apart at the beginning of the solar system. These metallic meteorites are often the easiest to identify after millions of years post-impact because they are quite different from terrestrial material, especially when it comes to their mass-to-surface area ratio. They are exceptionally heavy for their size since iron is a high-density metal: this is also why the Earth's core is nickel-iron. As planets form, the densest metals form gravitational centers, bringing more and more material into their gravitational pull. In the solar system's rocky planets, these dense materials are most often nickel and iron.

Most iron meteorites have distinctive, geometric patterns called Widmanstätten patterns, which become visible when the meteorite is cut and acid etched. These patterns are criss-crossing bands of the iron-nickel alloys kamacite and taenite that slowly crystalized as the core of the meteorites' parent bodies slowly cooled. Such large alloy crystallizations for mover millions of years and do not occur naturally on Earth, further proving that iron meteorites come from extraterrestrial bodies.