Stony

Stony meteorites, the most common type of meteorite, are composed of approximately 75 to 90 percent silicon-based minerals, 10 to 25 percent nickel-iron alloy, and trace amounts of iron sulfide. Stony meteorites account for 94 percent of observed meteorite falls; of the two subgroups, chondrites are the most abundant, making up approximately 86 percent of all falls.

Chondrites

Chondrites, the most abundant type of stony meteorite, contain many of the first objects to have formed in the solar system, such as calcium-aluminum-rich particles and chondrules (from which chondrites get their name). Their chemistry is very primitive because they have undergone very few chemical interactions with other objects since their formation. Chondrites also contain flecks of nickel-iron alloy.

Achondrites

Achondrites originated from another planet or asteroid, having been reformed from molten fragments that were flung into space as the result of another collision. Because achondrites closely resemble Earth rocks to the naked eye, they are rarely encountered as finds. Most achondrites in the Center's collection were observed falls.

Iron

Iron meteorites come from the core of large asteroids and are composed almost entirely of nickel-iron alloy, which is also a primary component of the Earth's core. Even though they account for only five percent of observed falls, they are more easily recognized than other types of meteorites.

Stony-Iron

Stony-iron meteorites contain approximately even amounts of silicates and nickel-iron alloy.

Pallasites

Pallasites form in between the silicate mantle, or outer shell, and molten metal core of an asteroid. The primary silicate mineral in pallasites is olivine, distinguishable by its greenish hue.

Mesosiderites

Mesosiderites are likely formed by collisions of metal-rich and silicate-rich asteroids.