[meteorite-list] From 1936 Issue: Meteorites Contain Large Amounts of Rare Metals

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Fri Aug 25 16:46:13 2006
Message-ID: <200608252043.NAA28216_at_zagami.jpl.nasa.gov>

http://www.sciencenews.org/articles/20060826/timeline.asp

>From the August 22, 1936, issue

METEORITES CONTAIN LARGE AMOUNTS OF RARE METALS

Discovery of notable amounts of the rare metals, gallium and
germanium, in the Earth's only imports from outer space, the
meteorites that fall from the sky, was announced by Dr.
Arthur S. King of the Carnegie Institution's Mt. Wilson
Observatory in a paper presented to the Society for Research
on Meteorites.

Emphasizing the usefulness of spectroscopic analysis instead
of the regular chemical and mineralogical methods for
determining the elements present, Dr. King found that iron
meteorites have some 19 elements within them, including in
largest quantities iron, nickel, cobalt, and copper.

In spectroscopic analysis, the different kinds, colors,
wavelengths, or spectral lines of light are viewed or
photographed and studied. Each element when heated intensely
flies its own kind of light "flag." The larger the amount
of the element present, the more intense is the brightness
of the spectral line.

The rare metals gallium and germanium in meteorite samples
produce very distinct spectrum lines, Dr. King explained.
While they are widely distributed in earthly rocks, they
occur in very small quantities.

Unlike irons of the Earth, iron meteorites are almost free
from chromium and manganese. Another interesting fact is
that traces of silver are present and those from Meteor
Crater in Arizona give the silver spectrum in considerable
strength.

Stony meteorites are quite different in composition from
the iron ones, although they contain a large percentage of
iron. Dr. King suggests that their iron explains why the
stony ones are not entirely consumed by heat when they
smash into the Earth's atmosphere.

A large amount of sodium is a striking feature of stony
meteorites as analyzed by the spectroscope. There is
nearly as much magnesium in them, and Dr. King suggests
that their high content of this metal, which burns with
a bright flame, accounts in large measure for the
spectacular features of meteoric falls that are seen
over large areas.
Received on Fri 25 Aug 2006 04:43:24 PM PDT