NWA-5738
Meteoritical Society Listing

NWA-5738 is shaped like a six-sided short brick, with the corners and edges somewhat rounded.
It is approximately 15cm long, 9cm wide and 8cm high.
When found, it was evidently 100% fusion crusted and weighted approximately 2200g.
It was purchased by Nicholas Gessler in Tucson in 2009.
One end has been freshly broken, probably by a hammer along a weak crack which shows caliche deposits.
The largest piece (2040g) is physically paired with the two next largest fragments (43g and 10g).
The smaller fragments (19 pieces weighin 24g) have been donated to UCLA and are being studied by Paul Warren and colleagues.
There is no reason to believe that the smaller pieces are not also physically paired, even though they have not been fitted to the largest.

22 Pieces:

2117g total acquired by N. Gessler comprising:

2040g retained by N. Gessler.
43g retained by N. Gessler.
10g retained by N. Gessler.
24g in 19 pieces donated to UCLA.

Top (photo A).

Bottom (photo B).

Side, top up, with broken end to left (photo C).

Side opposite, top up, with broken end to right (photo D).

Intact end (photo E).

Broken end (photo F).

Crossed stereo pair showing physical pairings of the three largest pieces (above, photo G).
Outlines of the three largest pieces are outlined in green (below, photo H).

Planar view of the windowed surface of the 43g piece showing a dark band approximately 1-2mm wide and 20mm long (photo I).
If this surface is tilted away from the viewer the band can be seen in cross-section (image below).

Sectional view perpendicular to the windowed surface of 43g piece showing dark band continuing underneath approximately 1-2mm wide and 20mm long (photo J)
Note that the crystals in this dark layer are perpendicular to the surface of that layer.
The layer continues in the 10g piece below.

Section view perpendicular to the windowed surface of 10g piece showing dark band 1mm thick continuing approximately 20mm in length (photo K).
The layer is a continuation of the layer in the 43g piece above.
Note that the crystals in this dark layer are perpendicular to the surface of that layer.

Plan location of sample of dark band on 43g piece sent to UCLA (8/22/2011) for thin section analysis.

Sectional location of sample of dark band on 43g piece sent to UCLA (8/22/2011) for thin section analysis.

Plan location of sample of dark band on 43g piece sent to UCLA (8/22/2011) for thin section analysis..
Yellow arrow shows point of view of photo below.

Sectional location of sample of dark band on 43g piece sent to UCLA (8/22/2011) for thin section analysis.
Yellow arrow shows point of view of photo above.

NEW PHOTOGRAPHS
4 NOVEMBER 2012
of three additional pieces (10g, 43g, 99g) loaned to UCLA:

Small fragment, 10 grams (also shown in other photos above).
Black seam, in cross-section orientation, showing crystaline growth perpendicular to the plane of the seam.

Medium fragment, 43 grams, (see other photos above).
Shows black inclusion, probably in an orientation perpendicular to the plane of the seam.

Large fragment, 99 grams, shown in-situ in photographs A (top right), B (top left), and C (left) before being pried loose.
Black inclusion exposed along one face of weathered crack in rock, seam is exposed in plan view, perpendicular to the longest direction of crystal growth in 10g fragment.