NEVADAMETEORITES
  NEVADAMETEORITES & SCIENCE  Page 2

METEORITES

Sonny Clary Collection

This thin section picture shows the accumulation of desert varnish on the exterior surface of

a meteorite. This meteorite is estimated to have arrived on earth 100.000 years ago.


Desert varnish has been considered to be a biogeochemical process that occurs in arid regions. Desert varnish is a patina composed of manganese, iron, and clays that form on surfaces of rocks exposed to the sun for thousands of years. It has been estimated that up to 10,000 years are required for a complete varnish coating to form in extreme arid desert

regions.

                                    Photo credit  ASU Center for Meteorite Studies

                    Ordinary chondrite displaying  an exterior coating of desert varnish.