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Re: (meteorobs) Tektites in South Africa??????
Bill,
Maybe this will help you out a little?
George
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FIELD TESTING FOR A METEORITE
By: George Zay
Revised: January 1997
On occasions you might find an FLR (Funny Looking Rock) that
could be a meteorite. Some meteorites may have great commercial
value. Increasing your degree of confidence before any prema-
ture announcements would minimize any embarrassments with a mis-
identification. It's kinda like coming across a large chunk of
gold and only after telling everyone about your find, you've
discovered that it's really Iron Pyrite (fools gold). There
are a few preliminary tests and observations you can make with-
out too much bother.
One property that all meteorites seemingly share to varying deg-
rees is their affinity for magnetic attraction. The Irons and
Stony/Irons will easily be attracted by just about any magnet.
It's some of the Stone meteorites that can get tough. Remember
that all meteorites are attracted by magnets. Even Stone meteor-
ites have small flakes of elemental iron. So it is possible for
these flakes to be influenced by a magnet. First you want to ac-
quire a magnet that's stronger than the one in grannys pot holder.
Then suspend your magnet from a thin string at a quiet location
(no wind or other influences). wait awhile for the magnet to be-
come totally motionless. Before you move your suspected meteorite
near the magnet several times, remove any jewelry or other possi-
ble metals that may be attracted by a magnet. Otherwise you might
find that a fistful of oatmeal can be of extra-terrestrial origin.
If the magnet moves or rotates, they you've cleared the first hur-
dle.
Besides the magnet test, there are a few things to look for. As
the meteor traveled thru the atmosphere, it's outer surface be-
comes hot enough to melt...only the surface/air contact areas will
become hot. The interior of a meteor will still be quite cold.
As the meteor fell, the flowing air moves the melted surface
around, creating what looks like thumb prints. They will also have
flow lines within the crust. A stony has a thicker crust than an
Iron. Also, meteorites are heavier than terrestrial rock per unit
volume. Besides being heavy, the crusts of fresh falls are black.
CHEMICAL METEORITE TEST FOR THE PRESENCE OF NICKEL
All Iron Meteorites contain nickel. Chrondrites also have enough
metal to test for nickel. A chemical test for the presence of nic-
kel can be made.
Caution is given here for some of the chemicals used. They can be
hazardous for those who don't respect them. If you aren't familiar
with the properties of the chemicals involved, seek guidance from
those that are. Wear protective gear...that is, rubber gloves,
goggles and apron. Dissolve less than 1 gram of the suspected met-
eorite in heated, concentrated Hydrochloric acid.
After it is dissolved, add to this solution a few drops of nitric
acid to oxidize the iron in solution. Then add a few drops of cit-
ric acid to prevent the iron from precipitating. Then neutralize
the solution with ammonium hydroxide. The solution should be clear
of precipitate...if not, filter the solution to obtain a clear li-
quid. To test for nickel, add a few drops of dimethyl gloxine to
the solution. If nickel is present, even in very small quantities,
the solution will turn bright cherry red.
PLACES FOR POSSIBLE METEORITE AUTHENTICATION
If at this point, your suspected meteorite has passed all the a-
bove you may want to have further tests performed to finalize it's
authenticity. These can be chemically done by professional labora-
tories. Do not break it open. Let the laboratory obtain their
small test sample via peaceful means. Below are addresses of a few
places who may do meteorite testing. I advise writing all of them
first to find their terms and cost (if any) etc. I can give no re-
commendations to any. I'm merely providing some addresses for your
consideration.
The American Museum of Natural History
Central Park West at 79th St.
New York, NY, 10024
Center for Meteorite Studies
Arizona State University
Tempe, Arizona, 85281
The Field Museum of Natural History
S. Lake Shore Dr.
Chicago, IL. 60605
Institute of Geophysics and Planetary Sciences
University of California
Los Angeles, Calif. 90024
Institute of Meteoritics
Department of Geology
University of New Mexico
Albuquerque, NM 87131
Lunar and Planetary Laboratory
Space Sciences Building
University of Arizona
Tucson, AZ 85721
National Museum of Natural History
Dept. of Mineral Sciences
Smithsonian Institution
Washington, DC 20560
Robert A. Haag
P.O. Box 27527
Tucson, AZ 85731
New England Meteoritical Services
P.O. Box 440-A
Mendon, MA 01756
Mineralogical Research Co.
15840 E. Alta Vista Way
San Jose, Ca 95127
Macovich Collection of Meteorites
1501 Broadway, Suite 1304
New York, NY 10036