If you think you
found a meteorite REV
12
If you
think you have found a meteorite and are looking for help identifying, there
are a number of steps I recommend you take before you start sending pictures
and such to people that might know. Note
that none of these tests prove a meteorite.
The tests,
should they prove positive, indicate you have a candidate specimen that might
be a meteorite.
My
suggestions below were born by my experience and are intended to help you
prior to bothering any one that you might consider an expert.
Note that
any one of the tests below are in no way conclusive in
the identification of a meteorite.
Collectively, if all of these tests are performed and the results are
positive, it only tells you that you might have a meteorite. At that
point in time, after the tests have been performed and show positive
results, then go bug an expert.
How you
found the meteorite is a good way to help start the process. A meteorite found with a metal detector will
normally sound off. A hunter will know
they have found something special.
However, rocks known as hot rocks will also sound off a detector.
Pictures – IMPORTANT
I put
pictures at the top of this page because more than not people take lousy
pictures that do no one any good.
Everyone gets excited when they think they have found a meteorite. It’s understandable. One of the first things that seems to happen is the finder will immediately send out
pictures of the rock asking people if they think it’s a meteorite, without any
clue as what is needed to determine if it is a meteorite. Pictures are more than often useless, because
they are out of focus, do not show a quality view of any kind and do not show a
quality view of the inside of the stone…a picture of the windowed area. Remember, we are trying to help you. We need quality close up pictures to see the
details needed.
A note about pictures. Please do not waste anyone’s time taking
pictures with a cell phone.
Most
professional investigators do not want pictures with cameras under 7
megapixels. When you take the picture,
place something of known size in the picture along with the rock. A penny, nickel, dime or
quarter, for example. The camera
should have and be in the macro mode for close ups. A close up is generally no further away than
5 inches from the specimen. Also, take
the pictures in natural sunlight. DO NOT
use zoom. Most people are not set up to
take good indoor pictures. Before
sending the pictures triple check it and insure it is in focus. Do not send pictures that are out of
focus. Take your time and do your
best. If you take lousy pictures, find
someone else to take the picture!
To review
taking pictures:
A. Outdoor natural lighting.
B. Camera 7 megapixels or higher
C. Macro (close up) mode. And if you have it, anti-shake mode
D. Put something next to the rock for
size comparison.
E. Don’t send pictures that are out of
focus! Check them.
F. Do not use zoom.
Magnetic -
Most all
meteorites are magnetic. The first step
is to determine if the specimen is magnetic.
Many earth rocks are magnetic and some are more magnetic than typical
ordinary chondrites. This single test in
NOT conclusive but is a step in the right direction. All meteorites I have found are magnetic.
Also note
that pure hematite is basically not magnetic.
The attraction to a magnet is very weak.
Magnetite (Fe3O4) is extremely magnetic.
Look and Feel – Often, rocks are found that are very
magnetic and have holes in them. Looking
at these holes, they look like the rock boiled at one time and gas was escaping
from them making holes all over them.
Baking a cake is probably a good example. It looks like a bunch of bubbles popped and
left holes in the process. These are not
meteorites. Every person that has held
my meteorites can tell me that they feel heavy and solid for their size. It is an obvious immediate feeling. Meteorites are usually dense, more so
relative to earth rocks of the same size.
There is absolutely no specific size or shape to a meteorite. It could be a whole piece or a broken
part. Visit my web site as well as
others[1]
and view the videos[2]
and pictures and read to gain knowledge.
The IMCA has pictures of
classified authenticated meteorites. Look!
Read! Do the research. Don’t
expect others to do this for you.
You need to
look at the rock under magnification. A x10 or better loupe is a good way to go. When you do this, you can really see better
detail. You can easily see earth rock
characteristics, such as pin sized holes.
You can easily see something that looked like metal to the naked eye is
only the crystal content reflection.
This look is really a pass-go. If
you see pin holes or the metal appearance seems to disappear under
magnification, it’s pretty much done at this point…it’s got a 99.9999% chance
of not being a meteorite.
Window – For me,
this is the must do step. Earlier, I mentioned
the 10x loupe. Really, any kind of 10x
magnification will work. You must see
inside a meteorite to determine the structure.
Shinny
metallic flecks: Care should be taken to distinguish between
true metallic grains and certain glittering crystals or flecks of minerals such
as mica or pyrites or quartz, etc.
Normally, with some experience and the 10x magnification, one can easily
see the differences by rolling the sample around in light to view it at different
angles. If you still can not distinguish
the metallic grains, you can take a hard sharp needle and by prodding while
looking under magnification, you can see if it crumbles or is ductile. The Nickle-Iron is
very ductile and will not crumble.
As you have
looked at my videos as well as others, you have seen the internal
structure. Does your rock have this
structure? Do you see the shinny metal
flakes? Do you see chondrules (spheres)? Do you see pin holes? If you see shinny metal flakes about 1mm in
size (or smaller) sprinkled around in the window, Super!! If you see chondrules or little round
objects, Super!!
Take your
time with this and think about it. It is
not necessary to cut a rock in half to create a window. Just look at the rock and find a spot on it
that is already a little flat. File or
grind or sand this area smooth and only deep enough to get past the outer part
of the rock. It normally will take a
diamond file to do this. A high speed
grinder with a cut-off wheel will do the job.
Be safe and do not squish the rock in a vise….that is a big no-no! If you file it or grind it, the view becomes
better if you sand it with something like 200 to 600 grit wet/dry
sandpaper. Note, for pictures, when you
complete your window it will be smooth, like a polished surface. If it is not smooth, take the time to make it
that way.
At this
point, if these tests above prove positive, you are in good shape. Honestly, this might be the time to consider
showing this rock to an expert or a hunter that has experience with meteorites. Not all people with detectors are experts and
most do not hunt meteorites. And trust
me, every “expert” was at the point you are right now at some time in their
past. Some of them have forgotten this.
Strike (Streak of the mineral) Test - There is one more test you can perform easily. This is a good diagnostic test for mineral
ID so you can do this to rule out an earth rock such as hematite or magnetite,
wad, etc. These rocks are oxides and
will leave a specific streak. They are
normally dense rocks and are often mistaken for meteorites. You need a piece of unglazed ceramic
(non-colored) in order to perform this test.
Find a coffee cup. On the bottom
of a coffee cup, there is normally a ring (where the cup sits on a surface)
that is not glazed. Take your specimen
and where you made this window (assuming you have a smooth surface) rub it on
this unglazed ceramic. You do the streak
test in the window area you made to eliminate the chance of any surface decay
or terrestrial contaminants affecting the color. Did it leave a streak? If it is a rusty reddish streak, it’s likely
Hematite (Fe2O3).
Hematite is a light to dark gray rock, often black when whole. A greenish black streak might mean pyrite.
If it’s a
grayish to black streak it’s likely Magnetite.
However, I want to point out that a meteorite sitting on earth for many
years “might” show a slight streak for a number of reasons. This one test by itself is not conclusive in
my opinion.
If no
streak at all, this is a very good sign.
Nickel Test – This is a favorite test for
meteorites for me. The search for
nickel! Most all meteorites contain an
amount of Nickel in them. It is not common
for an earth rock to contain nickel at the levels contained in meteorites. While there are chemical tests that can be
performed, they are destructive tests.
And, many people do not do this well and these tests are known to give
false positives. I am really talking
about these allergy test kits people used to determine if something they may
wear has nickel it, like a ring or necklace.
An old school lab nickel test is normally where you take a small sample
of the specimen (if a stony meteorite) crushing it finely in a mortar. Then you boil that in diluted nitric acid for
about two minutes and let it cool. Once
cooled, you would add ammonium hydroxide to render it alkaline. You would then filter it and treat the
filtrate with a few drops of dimethylglyoxime and if nickel is present the
result will be a bright pink color. This
even works for a very small amount of nickel.
It is because of this small amount of nickel that renders this test
inconclusive. If positive, it is a step
in the right direction, but not everything that is needed to be known. And, unless you are trained at handling chemicals
properly, I highly recommend staying away from chemical testing of any
kind…period!
XRF testing
is becoming common place and non-destructive.
I recommend this. I offer this
service for anyone who wants a Go / No-go test to determine nickel test. XRF stands for Xray
Fluorescence and is a non-destructive elemental analysis technique. Without going into any real detail, atoms
react when radiated. They become
ionized.
Energy is
an effect and each element responds differently. These differences can be measured.
This is how
I test for nickel. The report returned
to the client is a good document to provide when one is trying to have a
meteorite classified. It does give hope
to the scientist that they are not wasting their time and is a clean
professional approach for pre-classification work for a field engineer. Contact me if you would like this done with
your specimen.
So if
everything is positive, it is time to contact an expert or experienced hunter. In your report, include the test results you
performed above…all of them. Explain
your test. Just do not say that you
“performed all the tests”. Explain the
tests you performed because “performed all the tests” really means nothing. I can help with all pre-classification work
and possibly find a classifier.
As a final comment. In 1942, H.H. Nininger once wrote, “It is a job for an expert in the study
of these bodies. In fact, the beginner
should never be satisfied with his own judgment on any specimen until it has
been verified by a specialist, because once a mistake
is made and not corrected it continues to be the cause of mistakes on the part
of other persons who see the specimen.”
If this
page helped you or you have a suggestion to make it better, or want me to look
at your rock please contact
me and let me know.