[meteorite-list] AD: New Achondrite Fall

From: jason utas <jasonutas_at_meteoritecentral.com>
Date: Thu, 28 Jun 2012 13:29:10 -0700
Message-ID: <CAK837U2sSfOWUAc_7hN5s_Lna741TRZok0ycCW9u608JKxQaUg_at_mail.gmail.com>

Hello All,
I spent much of the past few weeks working on our website, but a
server crash late last week seems to have erased nearly all of my
recent edits. To help pass the time while the support folks sort
things out, I decided to re-upload some photos separately and make an
offering directly to the list.

The specimens offered here came from the first batch of stones
recovered from this fall. We purchased a 155.9 broken stone and
removed the broken portion of the stone (as well as a few extra
slices), leaving the stone ~2/3 intact.

The meteorite appears to be a primitive achondrite with an igneous
texture -- unlike nearly every other primitive achondrite known.
Acapulcoites, lodranites, and winonaites are typically known for their
triple junctions and well-defined olivine, pyroxene, and feldspar
crystals. The more primitive meteorites from those groups still
contain remnant chondrules, but they are all considered to be
metamorphic rocks, to varying degrees. This meteorite *could* be
related to those groups chemically and/or isotopically, but it is
structurally distinct and appears to be very unusual.

The overall color of the cut surface of this meteorite is a mottled
off-grey/pale lime-green, with abundant bright green crystals which
are 1) extremely difficult to capture with a camera and are 2) likely
chromium-rich pyroxenes of some sort. It contains very little
olivine.

Metal is heterogeneously distributed throughout the meteorite. It
varies in abundance from ~5%wt to >40%wt, and apparently forms solid
aggregates up to at least ~120 grams.

This stone was and is completely pristine. The cutting was performed
using denatured alcohol in order to prevent oxidation, and this stone
was recovered prior to the fall of any precipitation, which has
apparently been heavy of late.

I have gone through the red antarctic books, the blue antarctic books,
and have seen many strange meteorites since we started collecting in
1998. This one doesn't match anything I've ever seen.

I don't know how much more of this fall will become available; no new
material from this fall surfaced at the Ensisheim show, so my best
guess is that the total amount of material available to collectors
will likely be limited to a few kilograms. More could theoretically
turn up, but I doubt that any will be as pristine as this.

The following specimens are available.

-- Part-slices & end cuts --

0.059 grams - cut fragment, some crust, shock vein - $20
6 x 3 x 2 mm.
Photo 1: http://www.fallsandfinds.com/attachments/Image/Summer_2012_Fall/0.059_gram_cut_fragment/DSCN2207.JPG
Photo 2: http://www.fallsandfinds.com/attachments/Image/Summer_2012_Fall/0.059_gram_cut_fragment/DSCN2210.JPG

0.105 gram end cut - crusted, bright green crystal - $40 Note - very
small amount of epoxy on one edge of specimen.
7 x 4 x 3 mm.
Photo 1: http://www.fallsandfinds.com/attachments/Image/Summer_2012_Fall/0.105_gram_end_cut/DSCN2215.JPG
Photo 2: http://www.fallsandfinds.com/attachments/Image/Summer_2012_Fall/0.105_gram_end_cut/DSCN2217.JPG

0.498 gram end cut - shock vein, good green crystals - $175 Cut face
is not sanded, not quite flat. There is one rust spot on the
exterior, and the rear of the specimen is partly covered in very thin
epoxy layer that could be easily removed. A little fusion crust is
present on the exposed face of the shock vein.
15 x 7 x 5 mm.
Photo 1: http://www.fallsandfinds.com/attachments/Image/Summer_2012_Fall/0.498_gram_end_cut/DSCN2196.JPG
Photo 2: http://www.fallsandfinds.com/attachments/Image/Summer_2012_Fall/0.498_gram_end_cut/DSCN2197.JPG

1.641 gram part-slice with 25-30% crusted edge - $575 Note - minor
traces of clear epoxy on the edge from cutting. Similar in quality to
full slices, just smaller. Sanded on one side, wire-sawn on the
other.
25 x 16 x 1.5 mm.
Photo 1: http://www.fallsandfinds.com/attachments/Image/Summer_2012_Fall/1.641_gram_part_slice/DSCN2190.JPG
Photo 2: http://www.fallsandfinds.com/attachments/Image/Summer_2012_Fall/1.641_gram_part_slice/DSCN2191.JPG
Photo 3: http://www.fallsandfinds.com/attachments/Image/Summer_2012_Fall/1.641_gram_part_slice/DSCN2192.JPG
Photo 4: http://www.fallsandfinds.com/attachments/Image/Summer_2012_Fall/1.641_gram_part_slice/DSCN2195.JPG

-- Complete Slices --

1.145 gram complete slice with 90+% crusted edge - $450
27 x 11 x 1.5 mm.
This slice came from a crusted protuberance adjacent to the broken
face. It exhibits large areas of crust, but neither side of it is
sanded; the larger cut face is very slightly curved. It looks great
either way - one edge broke along the melt vein exposing shiny &
iridescent metal/sulfides. Good green crystals are visible on the
wire-sawn faces. No rust - think the second photo is reflecting
reddish due to the presence of sulfides.
Photo 1: http://www.fallsandfinds.com/attachments/Image/Summer_2012_Fall/1.145_gram_complete_slice/DSCN2200.JPG
Photo 2: http://www.fallsandfinds.com/attachments/Image/Summer_2012_Fall/1.145_gram_complete_slice/DSCN2201.JPG

*The second photo appears pale green, which is the meteorite's true color.

4.552 gram complete slice - 40% crust along edge - $1,355
40 x 32 x 1.5 mm.
Photo 1: http://fallsandfinds.com/attachments/Image/Summer_2012_Fall/4.552_gram_complete_slice/DSCN2166.JPG
Photo 2: http://fallsandfinds.com/attachments/Image/Summer_2012_Fall/4.552_gram_complete_slice/DSCN2165.JPG
Photo 3: http://fallsandfinds.com/attachments/Image/Summer_2012_Fall/4.552_gram_complete_slice/DSCN2164.JPG
Photo 4: http://fallsandfinds.com/attachments/Image/Summer_2012_Fall/4.552_gram_complete_slice/DSCN2162.JPG

6.104 gram complete slice - 90+% crust along edge - $1,830
41 x 36 x 1.5 mm.
Photo 1: http://fallsandfinds.com/attachments/Image/Summer_2012_Fall/6.104_gram_complete_slice/DSCN2173.JPG
Photo 2: http://fallsandfinds.com/attachments/Image/Summer_2012_Fall/6.104_gram_complete_slice/DSCN2174.JPG
Photo 3: http://fallsandfinds.com/attachments/Image/Summer_2012_Fall/6.104_gram_complete_slice/DSCN2177.JPG

11.700 gram complete slice - 100% crust along edge - $3,510
46 x 36 x 2.5 mm.
Photo 1: http://fallsandfinds.com/attachments/Image/Summer_2012_Fall/11.700_gram_complete_slice/DSCN2185.JPG
Photo 2: http://fallsandfinds.com/attachments/Image/Summer_2012_Fall/11.700_gram_complete_slice/DSCN2186.JPG
Photo 3: http://fallsandfinds.com/attachments/Image/Summer_2012_Fall/11.700_gram_complete_slice/DSCN2187.JPG
Photo 4: http://fallsandfinds.com/attachments/Image/Summer_2012_Fall/11.700_gram_complete_slice/DSCN2188.JPG
Photo 5: http://fallsandfinds.com/attachments/Image/Summer_2012_Fall/11.700_gram_complete_slice/DSCN2189.JPG

*Note -- this last full slice exhibits an odd inclusion. In the first
and second photos, there is an oval (very slightly) dark patch to the
left of the thick glass vein near its midpoint. That inclusion is a
very clearly-defined intergrowth of silicate minerals and troilite.
It is somewhat visible in the reflected light of the third photo. I'm
not sure what it might imply in terms of this meteorite's genesis, but
it is interesting.

It's not too often that a new meteorite (a fall, no less!) comes along
and...looks unlike any meteorite around. I don't know how much of
this will become available in the future, but I've heard reports that
the region in which it fell has been literally flooded for some time.
Since this meteorite is iron-rich, I can only imagine what future
material will look like. These specimens are pristine examples of a
very unusual meteorite.

Please allow an extra $4-5 for shipping depending on the specimen. A
membrane box is included with each specimen. Personal checks are
preferred, especially for larger purchases, but I do accept paypal.

Thanks,
Jason
Received on Thu 28 Jun 2012 04:29:10 PM PDT