Your subject title is enticing. Let's assume that the Albion meteorite is a high AU-Gibeon with crystal bearing vugs. What is fascinating to me is included in the following statements taken from yours and Bernd's messages:
"Of the more than 800 known iron meteorites, none have exhibited any form of vugs or "holes" within their Ni\Fe structure. To find them in an iron meteorite appears to "rock the boat" on the way we think of asteroid cores - the parent bodies of iron meteorites. "
Again from Bernd:
"We investigate two possible scenarios for the formation of the
open
cavities. Either the voids are primary features, such as vapor-filled
bubbles, that were entrapped by the solidification of the Fe,Ni alloy
and survived its period of exsolution, or they are secondary features
formed by the corrosion and removal of minerals in the solid iron.
Tle
primary nature of the vugs would require an entrapment of highly
fractionated fluids and their preservation during exsolution of primary
austenite grains in order to explain the difference in mineralogy
between large and small vugs. The secondary nature of vugs implies
that
the large and small vugs were initially filled with troilite (ubiquitous
troilite nodules in IVA irons) and minerals exsolved from the metal
(phosphides, carbides, or nitrides?) respectively. Later reaction with
a
gaseous carrier percolating through metal along grain boundaries
resulted in mobilization and redeposition of metallic elements in
troilite nodules. Most of the S escaped as gaseous species (COS or
H2S). Minerals of small cavities were leached out completely.
Neither
of these scenarios accounts for all observations, but both scenarios
are
inconsistent with formation by shock ubiquitous in many IVA irons
[4]."
You wrote:
"The pressures within a iron-nickel planetoid core (Earth,
asteroid, etc.) are sufficiently great that gases should not be able
to
exsolve. It is hard to believe that a few bubbles could develop,
much less
survive, under such severve pressures that would form a core and otherwise
prevent exsolution from occuring homogeneously through the specimen.
I think the vugs and voids are real and unique. I would
tend to think they
are more likely to be pockets of minerals or imperfections leached
out by
subsequent chemical reactions within the core or "chemical weathering"
(reactions from being exposed to other materials after being blasted
out of
the core by an impact). This is only a hunch based upon what
is known about the intense pressures and temperatures within an iron-nickel
core.
As an aside, some geophysicists have recently modelled the Earth's inner
core and predict that the iron-nickel is directionally aligned into
columns,
a feature that is not readily apparent from examining iron-nickel
meteorites."
Given the magnitude of new information, albeit undeciphered to date, provided by this specimen, or maybe I should say, the enigma of new pathways presented, I am somewhat surprised that there have not been comments on the list about this quizzical specimen. Before I ask my question, I would love to hear more discussion about this, which may provide my answer and some interesting dialogue.
Best regards,
Julia