Published online by Cambridge University Press: 11 August 2021
The first significant step in meteorite classification was taken in 1802 by British chemist Edward Howard who showed that the meteoritic stones and irons he analyzed all contained Ni. This criterion was used to distinguish meteorites from terrestrial rocks, but the reliability of this distinction was soon undermined by two essentially metal-free falls: the Stannern eucrite in the Czech region of the Austrian Empire in 1808 and the Luotolax howardite in Finland in 1813. It became apparent to researchers that, although most stony meteorites contained metallic Fe-Ni, a few did not. This realization somewhat hampered subsequent classification efforts because a few large collections included a handful of metal-free terrestrial rocks posing as meteorites. Some of these “meteorwrongs” were covered with dark crusts, probably desert varnish or weathering rinds.