The Meteorite

The Rice Northwest Rock and Mineral Museum is home to many “out of this world” meteorites, most of them prepared and presented by the Cascadia Meteorite Laboratory of Portland State University. On a visit to the museum, you will have a chance to touch our amazing Gibeon Meteorite from Africa. There is so much iron in that meteorite, it feels really cold to the touch.

Meteorites are naturally occurring objects that come from space and survive penetrating the Earth’s atmosphere. Most meteorites originate in the asteroid (an object in space too small to be a planet) belt between Mars and Jupiter, but some meteorites are pieces of Mars or the moon.

Every May, the Museum celebrates our annual Meteorite and Family Fun Day. Until them, let’s learn more about meteorites.

There are three main types of meteorites: stony, stony-iron and iron.

The most abundant type of meteorite is the stony meteorite, which accounts for over 90% of all recorded meteorite falls. The subgroup chondrites are most abundant. Iron meteorites account for ~5% of all meteorite falls.

Meteorite sizes vary greatly from small (dust) to large (5 to 7 miles wide). The frequency with which the Earth is bombarded by meteorites depends on the meteorite’s size. Small meteorites impact the Earth very frequently, whereas large meteorites impact much more rarely.

Meteorites are named after the locations where they are found. Oregon meteorites include an iron meteorite from Klamath Falls, a stony meteorite from Salem, an iron meteorite from Sams Valley, and an iron meteorite from Willamette.

Here is information about the specific types of meteorites.

Stony Meteorites

The stony meteorites are composed of mostly rocky material (silicate minerals) and contain a small amount of iron and nickel. There are two main types of stony meteorites – chondrites (have never been melted) and achondrites (melted and thus differentiated such that heavy metals sank to the core and the lighter silicates floated).

Stony-Iron Meteorites

The stony-irons are made up of an almost equal mixture of iron-nickel metal and silicate minerals. Pallasites are a common example of stony-iron meteorites.

Iron Meteorites

Iron meteorites are composed primarily of iron and nickel metal. These meteorites most likely represent the metallic cores of asteroid bodies.

More Information on Meteorites

To help you learn more about meteorites in general, here are some helpful educational resources and articles.

Rhodochrosite – The Inca Rose Stone

Among our many Exhibits in the Rice Northwest Rock and Mineral Museum is our popular Rhodochrosite specimens. Rhodochrosite is also known as Inca Rose Stone, Raspberry Spar, and Manganese Spar.

Rhodochrosite is a manganese carbonate (MnCO3). The carbonates are a group of minerals that contain the anion group CO32-, and are subdivided into the calcite, aragonite, dolomite or hydrated carbonate subgroups. Rhodochrosite belongs to the calcite subgroup. These carbonates are known for having rhombohedral symmetry, which results in the formation of rare rhombohedron shaped crystals.

The name rhodochrosite is derived from the Greek for rose-colored. Rhodochrosite is most commonly pink or red, but may sometimes occur as yellow, grey or brown crystals. Pink and red colors occur when the rhodochrosite has a high manganese content, but some substitution of iron in place of manganese causes other colors. Its density also depends on the amount of manganese present, with a lower density associated with low iron content. Continue reading