Lunar meteorite NWA 15604 is another beautiful cosmic discovery. This meteorite was discovered in August 2022 by a group of meteorite hunters in Nouadhibou, Mauritania, and with a total known mass of 2.3 kg, it is among the 329 officially approved meteorites classified as lunar.
Meteorite NWA 15604 is distinguished by its composition, which offers a glimpse of the Moon's geological past. It is made up of breccia, a type of rock composed of fragments of minerals or rocks joined together in a fine-grained matrix. This meteorite contains mineral fragments up to 3 mm in size, including anorthite, olivine and augite, along with a few fragments of melt.
The meteorite is composed of many brown fragments with no molten crust, indicating that it underwent a complex process when it entered the Earth's atmosphere. Every single piece we have on offer is interesting in some way and you won't get tired of looking at it up close.
It's geochemical composition is characterised by its varying iron and calcium content. For example, olivine has an iron to manganese (FeO/MnO) ratio of 82±7, while in low-Ca pyroxene the ratio is 55±5. Furthermore, the meteorite contains calcite plagioclase with a very high anorthite content (An96.2±0.5), which is rare and important for understanding lunar geology.
More on its composition here.