NWA 17364 Ordinary Chondrite Meteorite End Cut, LL3.10, 13.34g, Fusion Crust

Type 3.10 preservation with textured fusion crust

This 13.34g end cut preserves the full textural contrast between NWA 17364's rippled fusion crust exterior and its minimally altered chondritic interior. The fusion crust surface shows ablation flow patterns formed during atmospheric entry, while the cut face exposes discrete chondrules suspended in fine-grained matrix. The LL3.10 classification indicates minimal thermal metamorphism, preserving volatile-rich glass and primary igneous textures from the solar nebula.

The specimen's geometry as an end cut provides both display perspectives in a single piece: the melt-sculpted exterior formed during Earth atmospheric passage, and the interior record of accretionary processes that formed this material 4.567 billion years ago. The preserved crust occupies approximately 40% of the visible surface area, showing characteristic regmaglypts and flow lineations.

Chondrule assemblage and matrix structure

The cut face reveals well-defined chondrules ranging from submillimeter to several millimeters in diameter, characteristic of LL group ordinary chondrites. Individual chondrules retain sharp boundaries against the surrounding matrix, indicating limited solid-state recrystallization. Porphyritic olivine textures remain visible within larger chondrules, preserving igneous cooling structures from flash-heating events in the protoplanetary disk.

The fine-grained matrix between chondrules retains its primitive character, consistent with petrologic type 3.10. This low metamorphic grade preserves primary accretionary textures and volatile components that would be lost at higher thermal grades. Metal grains distributed throughout the matrix show minimal oxidation, typical of the low iron content that defines the LL (low metal, low total iron) classification group.

Scientific context

NWA 17364 belongs to the LL ordinary chondrite group, representing material from an asteroid parent body that accreted in the early solar system. The 3.10 petrologic subtype classification places this meteorite among the least thermally altered chondrites known, preserving near-primary nebular conditions. Only seventeen meteorites have received the LL3.10 classification according to Meteoritical Bulletin records, making specimens of this subtype scientifically significant for understanding pre-metamorphic asteroid composition.

Ordinary chondrites like NWA 17364 provide ground truth data for asteroid spectroscopy and thermal modeling. The preservation state of type 3.10 material constrains maximum temperatures experienced on the parent body surface or in shallow subsurface layers where thermal metamorphism remained minimal. Learn About Meteorites to explore how classification systems quantify metamorphic grade and what petrologic subtypes reveal about asteroid thermal history.

Frequently asked questions

Is this meteorite authenticated? NWA 17364 is classified in the Meteoritical Bulletin as an LL3.10 ordinary chondrite found in Mali in 2022. Classification was performed by Anthony Irving and Akira Yamaguchi at University of Washington and NIPR. Full classification data: NWA 17364. A certificate of authenticity from Treasure Coast Meteorite Co. is included with this specimen.

What does the 3.10 petrologic subtype indicate? The 3.10 designation represents minimal thermal metamorphism on a scale where 3.00 is completely unaltered and 3.9 approaches type 4. Type 3.10 chondrites retain primary glass, unequilibrated mineral compositions, and volatile elements lost at higher grades. Only seventeen LL chondrites worldwide have received this specific classification.

What is included with this specimen? The specimen weighs 13.34g and includes a certificate of authenticity from Treasure Coast Meteorite Co. No display stand is included unless separately noted.

Why is fusion crust significant on chondrites? Fusion crust forms during atmospheric deceleration when surface material melts and ablates. On chondrites, preserved crust provides textural evidence of entry angle, velocity, and atmospheric heating duration. The rippled texture on this specimen indicates rotational tumbling during descent.

What is the difference between LL, L, and H chondrites? The letter designations refer to total iron content and metallic iron abundance. H chondrites are high in both, L chondrites are low, and LL chondrites like NWA 17364 are lowest in both total and metallic iron. These groups represent distinct parent asteroids with different formation redox conditions.

Collector significance

LL3.10 chondrites represent the most primitive end of the petrologic type spectrum for low-iron ordinary chondrites. With only seventeen classified examples worldwide, specimens of this subtype offer access to minimally processed solar system material. This 13.34g end cut provides display-ready geometry, combining fusion crust preservation with visible chondrule structure in a single orientation.

The specimen's size and dual-surface presentation make it suitable for collection display while retaining the textural information that defines its scientific classification. Collectors focused on petrologic type series or building comprehensive ordinary chondrite reference sets will find few opportunities to acquire LL3.10 material. Browse additional primitive specimens in the Chondrites collection or explore metamorphic grade comparisons across Ordinary Chondrites.

Meteoritical Bulletin entry: NWA 17364 | Classification: LL3.10 Ordinary Chondrite | Find, Mali, 2022