NWA 17708 Howardite Meteorite Slice, 38.73g, Fusion Crust on 50% Edge, HED Achondrite from Vesta

Fusion crust preservation on a freshly classified howardite

This 38.73g slice of NWA 17708 preserves rippling fusion crust along roughly half its perimeter edge, documenting the specimen's atmospheric entry heating. The sanded interior face reveals brecciated texture characteristic of impact-mixed material from asteroid 4 Vesta's regolith. Contrasting lithologies appear as distinct clasts suspended in a fine-grained matrix, representing fragments of both eucritic basalt and diogenitic orthopyroxenite combined by ancient cratering events.

The fusion crust retention on a slice of this size provides both scientific documentation and visual appeal. Most sliced meteorites lose their exterior surfaces entirely during cutting and preparation, making this partial preservation noteworthy for display purposes.

Brecciation and mixed lithology structure

The polished face displays clear boundaries between eucritic clasts and diogenitic fragments, creating a mosaic texture formed by hypervelocity impacts on Vesta's surface approximately 4.5 billion years ago. The eucritic components represent basaltic crustal material from Vesta's differentiated surface layers, while diogenitic fragments originate from deeper plutonic cumulates rich in orthopyroxene.

The fine-grained matrix binding these clasts consists of comminuted material from both lithologies, pulverized and mixed during the impact gardening process that dominates airless body surface evolution. This mixing process transformed separate rock types into the polymict breccia now classified as howardite.

Scientific context of Vesta samples

Howardites belong to the HED achondrite group, confirmed by NASA's Dawn mission as originating from asteroid 4 Vesta, the second-largest object in the main asteroid belt. Vesta underwent complete differentiation early in solar system history, developing a metallic core, ultramafic mantle, and basaltic crust similar to terrestrial planets despite its relatively small diameter of 525 kilometers.

The howardite classification indicates this specimen formed through surface regolith processes rather than igneous crystallization. Impacts excavated material from various depths across Vesta's stratigraphy, mixing crustal eucrites with mantle diogenites to create the brecciated assemblage now found in NWA 17708. Studying these mixed samples helps planetary scientists reconstruct both Vesta's internal structure and its 4.5-billion-year impact history. Learn About Meteorites provides additional context on achondrite formation and classification.

Frequently asked questions

Is this meteorite authenticated? NWA 17708 received official howardite classification through analysis documented in the Meteoritical Bulletin. The classification confirms its composition as a polymict breccia of eucritic and diogenitic material consistent with Vesta origin. This specimen includes a certificate of authenticity from Treasure Coast Meteorite Co. verifying its classification and provenance. Reference: NWA 17708 in the Meteoritical Bulletin Database.

What does the fusion crust preservation indicate? Fusion crust forms during atmospheric entry when aerodynamic heating melts the meteorite's exterior surface, creating a thin glassy rind. The rippling texture visible on this specimen's edge indicates the surface experienced differential heating or ablation during its descent through Earth's atmosphere. Most slices lose all fusion crust during cutting, making this 50% edge coverage significant for both scientific documentation and aesthetic presentation.

What is included with this specimen? This listing includes the 38.73g NWA 17708 howardite slice, certificate of authenticity from Treasure Coast Meteorite Co., custom specimen card with classification details, and protective display case. No acrylic stand is included with this specimen.

How does howardite differ from eucrite and diogenite? Eucrites are basaltic achondrites representing Vesta's crustal material, while diogenites consist of coarse-grained orthopyroxenite from deeper plutonic layers. Howardites are polymict breccias containing fragments of both lithologies mixed by surface impacts, making them distinct from the monomict eucrite and diogenite classifications despite sharing the same parent body.

Display-worthy HED specimen for Vesta collections

At 38.73g, this slice provides substantial size for cabinet display while maintaining affordability compared to larger HED specimens. The combination of visible brecciation texture, partial fusion crust preservation, and fresh classification makes NWA 17708 particularly suitable for collectors building representative asteroid sample suites.

The newly classified status adds research interest, as material from 2024 finds often receives detailed analytical attention from the meteoritical community. Collectors focusing on HED Meteorites will find this specimen complements eucrite and diogenite samples by documenting the surface mixing processes that created Vesta's regolith layer. The fusion crust component adds visual distinction compared to fully polished slices, while the sanded face allows clear examination of the brecciated internal structure.

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