Collection
Classification: HOW (Howardite)
Pallasite (main group), based on texture, grain size of olivine and olivine composition
Observed fall: No
Year found: 2022
City, Country: Northwest Africa
Mass: 984 g
In collection
Weight #1 : 7,3 g
Certificate of authenticity: Yes (1)
The NWA 15682 meteorite is classified as a Howardite (HOW), belonging to the HED (Howardite-Eucrite-Diogenite) group of achondritic meteorites believed to originate from the crust of asteroid 4 Vesta. As a brecciated rock, NWA 15682 is composed of a mixture of eucritic and diogenitic fragments, indicating a history of significant impact events that have shattered and reassembled diverse rock types from Vesta’s surface and interior. This meteorite exhibits a heterogeneous texture with varying mineral compositions, including pyroxene, plagioclase feldspar, and olivine, embedded within a fine-grained matrix. The presence of these minerals reflects the volcanic and magmatic processes that once occurred on Vesta, while the brecciated nature highlights the dynamic collisional environment in the asteroid belt. Studying NWA 15682 provides valuable insights into the geological history and differentiation processes of Vesta, enhancing our understanding of planetary formation and the early solar system’s evolution.
When examining a Howardite meteorite under a light microscope, several distinctive features can be observed:
Eucritic Clasts: Mineral Composition: Dominated by pyroxene (typically augite) and plagioclase feldspar (andesine or oligoclase). Texture: Display interlocking, granular textures characteristic of basaltic rocks. Under plane-polarized light, eucritic minerals appear dark green to brown with high relief. Plagioclase feldspar appears lighter, often white to pale gray.
Diogenitic Clasts: Rich in orthopyroxene (enstatite) and often contain olivine. Orthopyroxene appears darker with high relief, while olivine shows a lighter green hue and higher birefringence.
Fine-Grained Silicate Composed of fine pyroxene, plagioclase, and olivine grains, often with minor amounts of iron-nickel metal and sulfides.
