編號 107915768

Gadamis 004 - “阿波罗16号月球样本” (月球富铁斜长岩,断裂碎裂的) - 29.46 g
編號 107915768

Gadamis 004 - “阿波罗16号月球样本” (月球富铁斜长岩,断裂碎裂的) - 29.46 g
This is an exquisite 29.46 gram end cut of Gadamis 004, one of the most interesting and rare classified lunar meteorites so far (together with NWA 13951, the famous “Starry Night” lunar).
Gadamis 004 originated as part of a 12.66 kg single stone found in the Libyan desert near the oasis of Ghadamis. An unusually anorthosite-rich Moon rock, Gadamis 004 is not your average lunar feldspathic breccia. What makes Gadamis 004 particularly fascinating is its unusually high abundance of anorthitic plagioclase. Microprobe analysis shows that cataclastic anorthitic plagioclase accounts for approximately 98–99% of the meteorite. The plagioclase itself is extremely calcium-rich, with a composition of approximately An96.0Ab3.8Or0.2, making it almost pure anorthite!! Only around 1–2% of the rock consists of olivine and pyroxene, occurring mostly as tiny blebs enclosed within the plagioclase.
The Meteoritical Bulletin classifies the meteorite as lunar ferroan anorthosite, cataclastic, noting that the compositions of its olivine, pigeonite and plagioclase fall within the Ferroan Anorthosite (FAN) suite. Particularly significant is the observation that its exceptionally high anorthite content and cataclastic texture are very similar to cataclastic ferroan anorthosites represented among the Apollo 16 samples. This makes Gadamis 004 a remarkable geological sample of the lunar highlands (the bright regions of the Moon), dominated by the ancient, feldspar-rich crust that formed early in the Moon's history.
The meteorite's texture tells another fascinating story. The original stone contains centimetre-sized anorthosite clasts separated by darker, fine-grained cataclastic zones, evidence of intense mechanical fragmentation and shock processing on the lunar surface or within the shallow lunar crust.
After being excavated from the Moon by a major impact, a fragment of this ancient lunar crust was ejected at more than 2.4 km/s (the Moon's surface escape velocity), left the Moon's gravitational influence, and travelled through space before eventually being captured by Earth's gravitational field and landing in the Libyan desert.
Shown in the last three pictures are in-situ pictures of the Apollo 16 lunar samples collected in April 1972. This lunar meteorite is as close to those samples as anything we have in private collections so far.
I am a member of the Meteoritical Society (#7743) and the Global Meteorite Association (#G0129) and have been collecting meteorites for more than 16 years.
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