Ash Shaqqah 002 — 月の水和変質を受けたトロクトライト質長斑岩 - 86.77 g

exaggeratedly nor to be small— this must be, without exaggeration, one of the most impressive lunar meteorites I have encountered so far. Its combination of coarse anorthitic plagioclase, abundant olivine, shock-related vesicles and vugs, and spectacular evidence of pre-terrestrial aqueous alteration makes Ash Shaqqah 002 one of the most interesting and rare specimens I've got in my collection.

Ash Shaqqah 002 was discovered in 2024 north of the Jaghbub Oasis, near the Libyan-Egyptian border. What initially appeared to be a 12 kg brownish desert rock turned out to be part of an extraordinary lunar strewn field. Further searching between October and December 2024 recovered numerous large masses, including stones weighing 10.5, 14, 16.6, 18.9, 19.6, 25.9, 32.9 and 45.7 kg, with the largest individual weighing 48.8 kg. The total approved mass is an astonishing 329 kg, distributed across a strewn field approximately 5 × 3.5 km in size.

The Meteoritical Bulletin classifies Ash Shaqqah 002 as a lunar troctolitic anorthosite, belonging to the Mg-suite of the lunar highlands. Its modal mineralogy is approximately: 80% anorthitic plagioclase, 15% olivine, 5% low-Ca pyroxene. The coarse anorthite grains dominate the meteorite, while most of the olivine occurs as sub-millimetre grains. The narrow compositional ranges of the olivine and pyroxene indicate that the material originated from a single plutonic lithology before being brecciated.

Electron-microprobe analyses give the plagioclase an extraordinary composition of approximately An96.9Ab3.0, while the olivine is approximately Fa19.1 and the low-Ca pyroxene approximately Fs16.9Wo4.2. These mineral compositions are consistent with a lunar highlands Mg-suite lithology.

Ash Shaqqah 002 also preserves abundant evidence of the violent impact environment of the lunar surface. Shock vugs and vesicles are ubiquitous, and plagioclase crystals frequently line their walls. Accessory Fe-Ni sulfide and kamacite are also present. These features are a reminder that this rock did not simply form and remain undisturbed in the lunar crust. It records a history of igneous crystallisation followed by intense impact-related fragmentation and brecciation before eventually being excavated from the Moon and delivered to Earth.

One of its most fascinating features of this meteorite: water-related alteration on the Moon!! Perhaps the most scientifically intriguing aspect of Ash Shaqqah 002 is the presence of orange-coloured, altered olivine within several multiphase clasts. This is particularly significant because the surrounding domains contain fresh, unoxidised metal. The Meteoritical Bulletin therefore concludes that the olivine alteration is unlikely to have resulted from pervasive terrestrial desert weathering and instead most likely occurred on the Moon, before the breccia was assembled.

Recent scientific work presented at the 57th Lunar and Planetary Science Conference likewise highlights the altered olivine in Ash Shaqqah 002 as evidence for endogenous alteration features in lunar meteorites, reinforcing the scientific interest of this material.

Ash Shaqqah 002 particularly stands out because it combines several features that are rarely encountered together in a single lunar meteorite: ancient lunar highlands crust + Mg-suite troctolitic anorthosite + impact brecciation + shock vesicles + abundant olivine + evidence for pre-terrestrial aqueous alteration.

The last three pictures show x10 pictures of some of the dark angular clasts from this sample (possibly aqueously altered phyllosilicates).

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.