NWA 17708 Howardite Meteorite Slice, 26.23g, Rippled Fusion Crust on 50% Edge

Rippled fusion crust and impact brecciation from Vesta

This 26.23g howardite slice preserves rippled fusion crust along approximately 50% of its edge surface, documenting atmospheric entry heating from the 2024 Mali recovery. One face shows sanded texture revealing the internal brecciated structure characteristic of howardite composition. The slice displays clasts of contrasting lithologies embedded in a fine-grained matrix, physical evidence of impact mixing between eucritic basaltic material and diogenitic orthopyroxene on Vesta's surface.

The specimen measures large enough to observe the relationship between dark eucritic fragments and lighter diogenitic components under magnification. Surface contrast between the rippled fusion crust and the sanded interior face provides clear visualization of both exterior heating effects and interior mechanical mixing processes.

Brecciated structure and weak magnetic signature

The slice exhibits polymict brecciation with angular clasts ranging from submillimeter to several millimeters embedded in a comminuted matrix. This texture results from repeated impact gardening of Vesta's regolith, mechanically mixing debris from both the upper basaltic crust and deeper orthopyroxenite layers. The howardite composition shows very weak to non-existent magnetic response, consistent with HED achondrites formed in an oxidized environment lacking metallic iron.

The sanded face reveals grain boundaries and clast margins where eucritic and diogenitic components meet. Fusion crust rippling along the edge indicates stable orientation during atmospheric passage, with aerodynamic heating creating wavelike surface texture before the meteoroid fragmented.

Scientific context

Howardites form the brecciated component of the HED meteorite suite, which NASA's Dawn mission confirmed originated from asteroid 4 Vesta through spectroscopic matching in 2011-2012. These meteorites sample both the basaltic crust and ultramafic mantle of a differentiated protoplanet that survived intact from the solar system's first 10 million years. Impact events on Vesta excavated deep craters, mixing surface basalts with mantle orthopyroxenites and ejecting the combined debris into Earth-crossing orbits.

NWA 17708 represents material from Vesta's regolith layer, where billions of years of impacts mechanically processed crustal and mantle fragments into the polymict breccia now classified as howardite. The specimen provides direct access to protoplanetary differentiation processes that operated when planets were still forming. Learn About Meteorites for broader context on achondrite formation and classification systems.

Frequently asked questions

Is this meteorite authenticated? NWA 17708 received official howardite classification through the Meteoritical Society's review process. The Meteoritical Bulletin entry: NWA 17708 documents the classification details. This specimen includes a certificate of authenticity from Treasure Coast Meteorite Co.

What does polymict brecciation mean? Polymict indicates the breccia contains fragments from multiple distinct rock types -- in this case, both eucritic basalt and diogenitic orthopyroxenite. These components mixed mechanically through impact processes on Vesta's surface rather than melting together, preserving individual clast identities within the matrix.

What is included with this specimen? The listing includes the 26.23g howardite slice, certificate of authenticity from Treasure Coast Meteorite Co., custom specimen card with classification details, and protective gembox display case.

Why does the fusion crust have ripples? Rippled or wavelike fusion crust texture forms when a meteoroid maintains stable orientation during atmospheric entry. Aerodynamic heating creates surface flow patterns in the melted exterior before the meteoroid breaks apart, freezing the ripple pattern as the crust rapidly cools.

Collector significance

Howardites represent less than 8% of all classified meteorite falls, making them substantially less common than ordinary chondrites or iron meteorites. This specimen combines display-quality size at 26.23g with preserved fusion crust, providing both scientific interest and visual appeal. The sanded face allows direct observation of the brecciated interior structure, while the natural fusion-crusted edge documents atmospheric entry processes.

NWA 17708 entered the collection market following 2024 recovery in Mali, offering recent classification data and fresh material for collectors building HED suites. The specimen serves both as a Vesta sample and as documentation of regolith processes on differentiated asteroids. Browse additional confirmed Vesta material in our Howardites collection and explore related specimens in the HED Meteorites category.

Meteoritical Bulletin entry: NWA 17708 | Classification: Howardite | Find, Mali, 2024