Specimen is an individual of this meteorite, with well visible coarse crystalline structure.
On the Meteoritical Society Database, NWA 12471 is reported as follows :
Petrography : Blocky aggregate of pyroxene and plagioclase with typical grain size 800 µm. FeNi metal, and its terrestrial weathering products, is visibile as droplets in the silicates and along silicate grain rims. Carbon polymorph is present close to grain rims as patches up to 100 × x500 μm.
Geochemistry : Olivine Fa22.5 (n=2), rim Fa10.4 (n=1). Pyroxene Fs18.9Wo10.5 (n=2).
Classification : Ureilite
Compared to most other meteorites, ureilites tend to have a high percentage of carbon (average 3%) in the form of graphite and nanodiamonds. The diamonds, which are rarely more than a few micrometres in diameter, are probably the result of high pressure shockwaves produced by collisions of the ureilite parent body with other asteroids.
According to one theory, Ureilites were formed in the interior of a parent body with cumulate crystals that formed crystal layers. Support for this comes from some ureilites in which the grains are aligned in a preferred orientation. Another suggestion is that ureilites represent a residuum of unmelted material after a partial melt liquid was drawn off. Yet other ideas are that they are unprocessed materials which never melted or that they are mixtures of carbonaceous chondrite and basaltic rock melts. It remains unclear whether ureilites originated on different parent bodies or in different regions of a single body.
Sent with signed certificat from original owner.
- Main Mineral/ Name Meteorite
- NWA 12471 - Ureilite - Primitive
- Mineral Form/ Type Meteorite
- Achondrite Meteorite
- 7.7 g
- Origin (Region/ City)
- Individual, as found
- Origin (Country)