碧玉和瑪瑙 火焰- 4082 g - (3)
編號 81966443
Sebkha el Melah 001 頑火輝石無球粒隕石(奧氏輝石) 無粒隕石 - 5 g - (1)
編號 81966443
Sebkha el Melah 001 頑火輝石無球粒隕石(奧氏輝石) 無粒隕石 - 5 g - (1)
Physical characteristics: This meteorite consists primarily of clusters of coarse, interlocking enstatite crystals with a pegmatitic texture. Individual crystals are cm-sized, many showing distinct cleavage planes and traces. Some enstatite crystals are milky-white in color, while a few are colorless translucent to transparent and gemmy. The enstatite crystals separate from the clusters easily, and the largest single crystal weighed 45 grams and was approximately 5 cm long and 2 cm wide. There are also scattered dark-colored patches on some of the crystals. Significant amounts of smooth cream-colored to white fusion crust are visible, although some fusion crust is dark-colored. No vesicles are present. The meteorite appears to be unbrecciated.
Petrography: (A. Ross and C. Agee, UNM) Electron microprobe analyses and reflected light microscopy show that enstatite makes up approximately 98% of this meteorite. Scattered small diopside grains were detected. A single olivine grain was found in the sample microprobe mount. Small grains of kamacite, taenite, schreibersite, Ti-troilite, troilite, and daubreelite were the only accessory opaques observed. No other sulfides were detected. No feldspar was found in the microprobe mount.
Geochemistry: (A. Ross, UNM) Enstatite Fs0.0±0.0Wo0.9±0.1, n=6; diopside Fs0.0±0.0Wo45.5±0.8, n=3; forsterite Fa0.0, n=1; kamacite Ni=4.3±0.8, Co=0.4±0.2 (wt%); taenite Ni=48.7, Co=0.11 (wt%).
Classification: Aubrite, non-brecciated (after Keil, 1989). This aubrite has one of the highest modal abundances of enstatite ever reported (~98%). The enstatite, diopside, and forsterite of this meteorite have some of lowest iron contents (below electron microprobe major element detection limits) ever documented in an aubrite.