Why this rock is probably not a meteorite:

We're looking at the sawn face of a pretty rock, but it's not a meteorite.  The matrix is red, indication the presence of highly oxidized iron (ferric iron, Fe3+).  Most meteorites are pieces of asteroids, and highly oxidizing conditions don't occur on asteroids (no oxygen atmosphere).  That's why many meteorites contain iron metal (Fe0) and are, consequently, magnetic.  Up close, one can see shiny things in this rock that look metallic, but they're not metal.  They're grains of sulfide minerals.
What is it?

This is a terrestrial sedimentary rock. Sulfide minerals are common in sedimentary rocks.  If it weren't so red, it would resemble some lunar meteorites in that the clast size is highly variable and most clasts are rather angular.  In detail, the clasts consist of potassium feldspar (pink) and quartz (whitish), which are rare to absent on the Moon and asteroids. It is conceivable that a rock that looks like this occurs on Mars, but none have been discovered among meteorites.


Prepared by:

Randy L. Korotev

Department of Earth and Planetary Sciences
Washington University in St. Louis

Please don't contact me about the meteorite you think you’ve found until you read this and this.