[meteorite-list] M.C.'s Babb's Mill (Blake's Iron) on EBay

[bernd.pauli at paulinet.de]

Hello All,

Here is another American classic I couldn't resist yesterday. Well, I had been
watching it for several days already and I had tried to ignore it after I had
recently bought a 0.95-gram partly crusted SNC individual from Marcin and
that terrific SNC slice I got on Ebay from Jim Strope. See here if you haven't
seen it yet:

http://www.rocksfromspace.org/January_19_2008.html

In vain did I try to ignore Babb's Mill, which is also known as Blake's Iron and
not to be confounded with Babb's Mill (Troost's Iron). I had read so often about
these two ataxites, I had seen a picture of the cigar-shaped main mass of Blake's
Iron in one of my very first books on meteorites (Heide's Kleine Meteoritenkunde,
1957, p. 80) that I did not want to miss out on an iron I have never before seen
offered (if I remember correctly) since I started collecting meteorites about 25
years ago.

Babb's Mill (Blake's Iron) has a nickel content of 11.8% Ni whereas Troost's
is richer in nickel (17.5%). As the meter-long cigar-shaped mass of Blake's
Iron had been dug up not far from Troost's Iron and as they are both of them
ataxites, Brezina assumed they were one and the same iron. Maybe Christian
or Alex can post a picture of this "cigar" which now resides in the Vienna
collection (weight: 128.7 kg).

The German meteoriticist E. Cohen [hence the name "cohenite" for the carbide
(Fe, Ni)3C] and his coworkers were the first to notice there was a noticeable
difference between both irons in nickel content. 

Berwerth (1918) even concluded that Blake's Iron was an artificial product and
thus not meteoritic. But Vagn Buchwald restored its good reputation and showed
that Blake's Iron was definitely of cosmic origin (and completely different from
Troost's Iron).

According to Buchwald, "etched sections display an homogeneous ataxitic structure
without visible inclusions of troilite, schreibersite, graphite or silicates" and
"high magnification reveals a polycrystalline mosaic of kamacite and taenite grains."

But, why don't you look for yourselves if interested. There are still 3 specimens that
Michael Cottingham is offering on EBay. My 0.45-gram slice should now be on its way
across the Big Pond.

Reference:

BUCHWALD V.F. (1975) Handbook of Iron Meteorites, Volume 2, pp. 284-285.


Ataxitically yours,

Bernd