Northwest Africa 10727 (NWA 10727)

(Northwest Africa)

Purchased: 2016

Classification: Ordinary chondrite (H3)

History: A complete 90.3 g fusion crusted stone was purchased in Erfoud, Morocco, Feb. 2016. Thomas Webb acquired the stone from a meteorite prospector in 2016.

Physical characteristics: The irregularly shaped stone is 95% crusted with a brownish-black fusion crust. Interior of cut face shows numerous distinct chondrules and abundant fresh metal (~10 vol%). Matrix material on cut face is light to dark brown.

Petrography: Description and classification (A. Love, App): Sample is dark-colored and displays numerous close-packed unequilibrated chondrules of varying size (avg. diam. 453 μm, 120-1552 μm, N=87). Porphyritic chondrules show zoned phenocrysts, isotropic glass and turbid mesostasis. Many chondrules display fine-grained rims composed of clastic materials, metals and sulfides. Matrix occurs as a mixture of clastic and amorphous silicates and fine-grained metals.

Geochemistry: (A. Love, App) Fa_17.6±12.6 (Fa_0.7-33.4) N=20, Cr₂O₃ in ferroan olivine is 0.12±0.20; Low Ca pyroxene Fs_16.1±10.2Wo_2.0±1.7 (Fs_2.1-36.0, N=25).

Classification: Ordinary Chondrite (H3 S1 W1) Chondrule size and abundant metal are consistent with H chondrites. Isotropic glass in porphyritic chondrule mesostasis is present 3.3-3.5. Red CL in chondrule olivine is present, but not common 3.2-3.4 (Huss et al., 2006). Yellow mesostasis present CL in mesostasis 3.2-3.4. Based on histograms Cr₂O₃ contents within ferroan olivines from Fig. 4 in Grossman and Brearley (2005), the sample is above type 3.2. Matrix is opaque and textural equilibration is cryptic if present. PMD of olivine=63.9. PMD of Opx=30.79 <3.1. Petrologic subtype is estimated as H3.3.

Specimens: Webb holds the main mass. Two slices weighing 18.56 g and one polished thin section are on deposit at App.