Why this rock is probably not a meteorite:
1) It's too angular. There appears to be some glass, but it doesn't
appear to be a fusion crust. Fusion crusts develop over flat, smooth
surfaces.
2) The rock's texture resembles that of a lunar regolith
breccia, particularly ALHA 81005.
In detail, however, there are too many big clasts (white) and not
enough small clasts. The rock particles in the lunar regolith are
unsorted - there is a complete range of sizes from big to small. There
are only a few small clasts in the dark matrix of this rock. In the
lingo of sedimentary petrology, the grain size distribution of the
clasts in this rock is not that of the lunar regolith.
June, 2004
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What is it?
Can't tell from photo. There are several geologic processes on Earth
that can lead to rocks that resemble lunar breccias.
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Addendum - October, 2006
Results of "standardless" EDS (energy-dispersive X-ray
spectroscopy)
received September, 2006. Values are oxide percents.
| sample |
Al2O3 |
SiO2 |
SO3 |
K2O |
CaO |
MnO |
FeO |
sum |
| 1 |
4.18 |
57.4 |
2.29 |
1.72 |
26.70 |
5.38 |
2.33 |
100.00 |
2 |
4.51 |
60.7 |
1.13 |
1.66 |
25.36 |
4.61 |
2.04 |
100.00 |
3 |
0.07 |
97.7 |
0.30 |
0.45 |
0.48 |
0.33 |
0.66 |
100.00 |
The person who sent me the photo, a gentleman from Sweden, has sent
me more than 1300 e-mail messages since February of 2003. Each one
has been accompanied by numerous photographs of rocks he claims
to be lunar (or sometimes martian) meteorites. I've urged him to
send me a sample for analysis. Twice he has said that he would do
so, but I have not yet received a sample that I can examine or analyze.
He has, however, had some samples analyzed by energy dispersive
X-ray spectroscopy and has sent me the results, which I've reproduced
in the table above.
EDS is an inexpensive, but non-ideal method for analyzing rocks.
It provides only an incomplete, semiquantitative (not exact) analysis.
Because no results are reported for Na2O and MgO, I presume their
absence in the reports (example below for sample 2) means that
their
concentrations were not determined because, as "light"
elements, no X-ray signal was obtained. The sum of the elements
that were determined have been normalized to 100% (see report
below).
We can reasonably assume that the concentrations of Na2O and MgO
are each a few percent.
The compositions of the analyzed samples are inconsistent with any
kind meteorite. Concentrations of SiO2,
SO3, K2O, CaO,
and MnO, are much too high for any kind of meteorite. Sample 3,
presumably one of the white clasts, is clearly a piece of quartz,
which does not occur in meteorites.
For samples 1 and 2, FeO is low, as in some lunar meteorites, but
CaO/Al2O3 (~6)
is much too high and FeO/MnO
(0.4) is much too low for any Moon rock.
Bottom line: These rocks are not meteorites. They
are terrestrial rocks or slags. If the MnO (manganese) concentrations
are really as high as ~5% and the FeO (iron) concentrations are
really as low as ~2%, then it is likely that they are man made -
the byproduct of some industrial process.
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