Enstatite chondrites (also known as E-type chondrites) are a rare form of meteorite thought to comprise only about 2% of the chondrites that fall on Earth...
Their oxygen isotopic compositions (intermediate between ordinary and carbonaceous chondrites) identical to the values recorded on Erath and Moon rocks, which could indicate they originally formed on the same area of the early pre-solar nebula.
NWA 4844 belongs to this group, the Enstatite Chondrites, which are are among the most chemically reduced rocks known, with most of their iron taking the form of metal or sulfide rather than an oxide. They tend to be high in the mineral enstatite (MgSiO3), from which they derive their name. They are also the driest objects in the solar system, consisting of only 0.01% water.
NWA 4844 is an EL-Melt rock, means an enstatite chondrite that have been almost fully melted by an impact event on its parent body/asteroid, long before to reach Earth.
Petrography: (J. Gattacceca, CEREGE) Highly recrystallized rock. No relict chondrule was observed. Main minerals are enstatite with typical size 150 µm and plagioclase to 100 µm. Metal and sulfides (including daubréelite) are found as µm sized spherical grains. Abundant vesicles with typical size 50 µm. Abundant terrestrial weathering products.
Geochemistry: Enstatite Fs0.7±0.1Wo1.4±0.1 (n=3). Plagioclase An16.4Ab79.2Or4.3 (n=2).
Delivered with a certificat from the original owner of the meteorite, as reported on the Meteoritical Bulletin
- Minéral principal / Nom météorite
- NWA 4844 - Classé comme "EL-Melt Rock" - Même composition isotopique d'oxygène que la Terre et la Lune -
- Forme minérale / Type météorite
- Chondrite enstatite
- 17×16×15 mm
- 4 g
- Origine (pays)