[meteorite-list] Official Announcement NWA 6077 is Paired with NWA 5400

[John higgins]

Official Announcement
 
NWA 6077 IS PAIRED WITH NWA 5400
 
North West Africa 6077 Description:
An olivine-rich assemblage with cumulate (or possibly metamorphic) texture 
exhibiting triple junction grain boundaries. Olivine (Fa30.2-30.7), 
orthopyroxene (Fs24.1-24.5Wo2.1-2.0), clinopyroxene (Fs9.4-10.0Wo44.0-43.5), 
altered kamacite, chromite, chlorapatite, Ni-bearing troilite and/or pyrrhotite. 
No plagioclase was found. Analysis conducted at the Carnegie Institution of 
Washington show that the oxygen isotopic composition of this specimen plots on 
the Terrestrial Fractionation Line. In conjunction with the mineral compositions 
and texture, this establishes that NWA 6077 is paired with NWA 5400.
 
The averages of the two Oxygen Isotope Results are: 
d17O = 2.780, d18O = 5.358, D17O = -0.019 (all in per mil)
 
This brachinite was recovered out of Morocco in 2008 as one whole stone and 
purchased by John Higgins. It was submitted for classification to Dr. Tony 
Irving and was given the provisional classification number of NWA 6077. This 
meteorite has a modest TKW of less than 1000g after the type specimen was 
removed.
 
Personal Notes: Although I suspected that the two were possibly paired due to 
similarities in visual observations and classification compositions, I felt it 
was important to wait for secondary Oxygen Isotope results to come in which have 
recently confirmed the results beyond a reasonable doubt. There was also another 
important factor besides Oxygen Isotope testing that had to be taken into 
account. Orthopyroxene which is present in NWA 5400 was missed the first time 
around in NWA 6077 because it looks identical to clinopyroxene in back-scattered 
electron images. However further in-depth microprobe studies of the thin section 
have confirmed the presence of orthopyroxene, and are now noted in the updated 
description. I feel that making a self pairing based upon my own 
visual observations, is not only unethical, inappropriate, and akin to pirating, 
but would only feed the controversies regarding this meteorite without the 
scientific testing data to back up such speculation, such action would be 
premature, immoral and unfair to Greg Hupe and NWA 5400 after all the time and 
effort he put into the study of what has become one of the most important 
meteorite finds in history.
 
Have a Great Day!
John Higgins
IMCA#9822