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

[Ron Baalke]

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.