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Roberts Massif 04186
Basic information Name: Roberts Massif 04186
     This is an OFFICIAL meteorite name.
Abbreviation: RBT 04186
Observed fall: No
Year found: 2004
Country: Antarctica [Collected by US Antarctic Search for Meteorites program (ANSMET)]
Mass:help 4.6 g
Antarctic Meteorite Newsletter:  AMN 29(2)  (2006)  IIE?
Meteoritical Bulletin:  MB 92  (2007)  Iron-IIE?
Recommended:  Iron, IIE?    [explanation]

This is the only approved meteorite classified as Iron, IIE?.
Search for other: IIE irons, Iron meteorites, and Metal-rich meteorites
Comments: Approved 1 Sep 2006
Writeup from AMN 29(2):
Sample No.: RBT 04186
Location: Roberts Massif
Field No.: 16233
Dimensions (cm):   2.0x1.0x0.5
Weight (g): 4.622
Meteorite Type: Iron-IIE (?)

Macroscopic Description: Tim McCoy and Linda Welzenbach
Sample is very irregularly shaped with ~1 mm weathered (orange colored) silicate inclusions in surface cavities and fractures. Surface of the metal is highly oxidized.

Thin Section (,2) Description: Tim McCoy
The section consists dominantly of metal, with subequant kamacite grains ranging from 200 µm to 3 mm in maximum dimension. In two places, lamellar kamacite with a bandwidth of ~200 µm is bounded by a coarse plessitic texture. Included within the metal are individual silicate grains of ~100 µm in dimension and polyminerallic clusters up to 1 mm. The silicates include olivine (Fa18-20), pyroxene (Fs16-19) and plagioclase. A barred texture suggestive of relict chondrules was found in one area. Also found in the metal, although not observed in association with the silicates, are phosphates, including both whitlockite and chlorapatite. The largest of these is a vein-like structure on the edge of the specimen and protruding inward ~3 mm. The meteorite may be related to the IIE irons.

Thin Section Images

Reflected Light Reflected Light Reflected Light
RBT 04186 - Reflected Light RBT 04186 - Reflected Light RBT 04186 - Reflected Light
Reflected Light Reflected Light
RBT 04186 - Reflected Light RBT 04186 - Reflected Light

Lab Images

RBT 04186
RBT 04186 Image South

Data from:
  Table 3
  Line 1082:
Mass (g):4.6
Class:Iron-IIE (?)
Fayalite (mol%):18-20
Ferrosilite (mol%):16-19
Search for this meteorite in the NASA/JSC database (U.S.):   
References: Published in Antarctic Meteorite Newsletter 29(2) (2006), JSC, Houston
Published in Meteoritical Bulletin, no. 92, MAPS 42, 1647-1694 (2007)
Find references in NASA ADS:
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Photographs from AMN:
JSC A photo is in the write-up above


     This is 1 of 40773 approved meteorites from Antarctica (plus 4570 unapproved names)

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