Description
Northwest Africa 14542 (NWA 14542)
(Northwest Africa)
Purchased: 2021 Aug
Classification: Rumuruti chondrite (R3)
Physical characteristics: Crusted stone. Cut surface reveals a dark interior with grayish chondrules set in an abundant dark matrix.
Petrography: (J. Gattacceca, CEREGE) Brecciated chondrite with well-delineated chondrules, mostly porphyritic type and less commonly radial pyroxne and barred olivine types, with apparent diameter 530±240 µm (n=31) set in an abundant iron-rich fine grained matrix (68 vol% by point counting, n=248). Sulfides, both troilite and pentlandite, are abundant in the matrix where they form spherical grains to 500 µm, in chondrules, and around chondrule rims (5 vol% by point counting, n=248). Magnetite is less abundant and associated with sulfides. No metal was observed. No CAI was observed.
Geochemistry: Olivine Fa31.6±9.7, range Fa14.7-42.7, FeO/MnO 82.9±27.2, Cr2O3 0.30±0.42 wt%, NiO 0.18±0.13 wt%(n=15). Matrix olivine Fa51.5 (n=1). Low-Ca pyroxene Fs15.1±7.7Wo1.0±0.6 (n=4). Magnetite Cr2O3 0.86 wt% (n=2). Defocused matrix FeO 42.3 wt%, analytical total 100.3 wt%.
Classification: Rumuruti chondrite (R3)
Specimens: Type specimen at CEREGE, main mass with Pierre-Marie Pelé.
| Place of purchase: | Guelmim |
| Date: | P 2021 Aug |
| Mass (g): | 522.5 |
| Pieces: | 8 |
| Class: | R3 |
| Weathering grade: | low |
| Fayalite (mol%): | 31.6±9.7 (n=15) |
| Ferrosilite (mol%): | 15.1±7.7 (n=4) |
| Wollastonite (mol%): | 1.0±0.6 |
| Magnetic suscept.: | 3.28 |
| Classifier: | J. Gattacceca, CEREGE |
| Type spec mass (g): | 24.1 |
| Type spec location: | CEREGE |
| Main mass: | Pierre-Marie Pelé |
| Finder: | anonymous |
| Comments: | work name PM21-1; submitted by Jérôme Gattacceca |
