[meteorite-list] AD: Special NWA 5475 a fine, low-shocked CK

From: Martin Altmann <altmann_at_meteoritecentral.com>
Date: Sun, 1 Feb 2009 18:27:35 +0100
Message-ID: <00ff01c98492$5ff456f0$177f2a59_at_name86d88d87e2>

Dear collectors,

High time for a Special to assuage the melancholy of the stay-at-homes, who
longingly watch the pictures and videos of the ongoing show in sunny Tucson.

To warm the collector's heart we pitch on today a fine and new CK4/5:
NWA 5475

Among the carbonaceous chondrites the CKs belong into the family of the CVs
and COs
(and in fact with TNZ 057 and NWA 2900 we have breccias on hand, which
probably are composed by CK and CV material).

The main differences are, that the CKs contain much less carbon, visually
they can be told apart by the small number of chondrules, also CAIs are very
sparsely found and their often dull appearance.
That darkness is caused mainly by iron oxides, as CKs show a higher
oxidation than CVs and Cos, and sulfides;
additionally they often are darkened by shock.

But with NWA 5475 we have now a member of that group, which is with S1 only
very weekly shocked.
Noticeably it displays very distinct chondrules and seems to have more of
them than many of the other CKs.
With a weathering grade of W2/3 it is fresher than the average.

The CKs are still a rare affair!

32 years of Antarctic hunts yielded not more than 5.2 kgs
(104 numbers, but endless pairings - the Elephant Moraine 90001 pairing
group comprises alone 40 numbered crumbs).
With Karoonda and Kobe we have so far only 2 observed falls,
and all non-Antarctic CKs together - 76 numbers and finds, many pairings
among them - weigh together 101 kgs,
whereof 72kgs were contributed by Karoonda and HaH 280/281.

All in all, regarding the combined tkws, one can say, that the stuff is rare
like Mars.

Here again the data

NWA 5475
Morocco 2008
CK4/5
S1, W2-3
tkw 178g

The specimens waiting to be added to your collection are complete cross
sections through the stone, grinded on both sides with partially preserved
old fusion crust,
and the two endcuts.
They are priced at an inexpensive 16$ per gram and 15$/g for the endcuts.


http://www.chladnis-heirs.com/specials/special-nwa5475.html


Enjoy!

Stefan Ralew & Martin Altmann
Chladni's Heirs
Munich - Berlin
Fine Meteorites for Science & Collectors
http://www.chladnis-heirs.com
Received on Sun 01 Feb 2009 12:27:35 PM PST