Why this rock
is not a meteorite:
Well, now, this is annoying. Right now (Nov 12, 2007) there's a guy
who's trying to sell 7 rock pieces on e-bay as
lunar meteorites. He has the nerve to use diagrams from MY
web site on lunar meteorite compositions to add credence to his
claim that the rocks are meteorites from the Moon. (This is the same
guy who tried to sell no. 223 as a mesosiderite.)
The ads make the logical error of showing that the composition* of
the alleged lunar meteorites does indeed plot on the trend of lunar
meteorites on ONE of the plots I use to classify lunar meteorites,
Al2O3 vs FeO+MgO (or Al2O3 vs. Fe2O3). However, the composition falls
far off the trends for MgO/FeO (=0.15),
Fe2O3/MnO (=23), K2O (=1.27%),
and Cr (138.8 ppm Cr2O3 = 95 ppm
Cr). This as a great example of selective validation. As I say on
my "Chemical Composition of Meteorites"
web site, "If you have a meteorite, its composition must be consistent
with ALL of the chemical-composition
parameters shown here, not just some of them!"
By the way, the photo on the right is one I lifted from the e-bay
ad and "improved."
* "SiO2 49.27% AL2O3 17.38% FeO 18.83% MgO 2.84% Na 0.94%
P2O5 0.50% SO2 0.30% K2O 1.27% CaO 6.17% TiO 0.95% MnO 0.84% ... Cr2O3
138.8 ppm CoO 847.6 ppm NiO 197.9 ppm..."
|
What is it?
Hard to say. With 17.38% Al2O3, it's not an olivine gabbro, as claimed
in the ads.
|
|
|
