NWA 17707 Ordinary Chondrite Meteorite Slice, LL4, 30.37g, Preserved Chondrules

Full cross-section of low-iron chondrite

This 30.37g slice captures a complete cross-section through NWA 17707, an LL4 ordinary chondrite classified in 2024. The specimen displays abundant chondrules distributed throughout the matrix, preserved in their original arrangement from 4.5 billion years ago. Light-colored spherules contrast against the darker groundmass, creating a visual record of the solar nebula's earliest solid materials.

The slice format exposes internal structure that remains hidden in exterior specimens. Chondrule boundaries appear sharp where thermal metamorphism stopped short of complete recrystallization. The LL designation indicates low total iron and low metal content compared to other ordinary chondrites, while the type 4 classification marks the threshold where these primitive structures begin to blur but have not yet disappeared.

Chondrule preservation and matrix structure

Individual chondrules range from sub-millimeter to several millimeters across this section. The type 4 metamorphic grade means these spherules retain their boundaries and internal textures, though secondary minerals have begun to homogenize between grains. This intermediate state makes LL4 chondrites valuable for studying the transition from unaltered to thermally processed material.

The matrix between chondrules shows fine-grained minerals that recrystallized under heat while the parent asteroid remained intact. This metamorphism occurred through radioactive decay and impact events, not atmospheric entry. The slice reveals this heating was sufficient to alter mineral chemistry but insufficient to destroy the fundamental architecture of these ancient droplets.

Scientific context

Ordinary chondrites like NWA 17707 formed from dust and molten droplets in the solar nebula before planets existed. The LL group contains less metallic iron than H or L chondrites, suggesting formation in a region of the asteroid belt where metal condensation was limited. Type 4 samples occupy a middle ground in the petrologic sequence, which runs from type 3 (least heated) to type 6 (most metamorphosed without melting).

The low metal content affects both appearance and density. LL chondrites typically show muted colors compared to their iron-rich relatives, and they lack the metallic flecks that dominate H chondrite surfaces. This composition reflects local conditions in the protoplanetary disk where temperature and pressure determined which materials could condense into solid form. Understanding these variations helps reconstruct the chemical gradient that existed across the early solar system. Learn About Meteorites provides additional context for how classification systems organize these ancient materials.

Frequently asked questions

Is this meteorite authenticated? NWA 17707 received official classification as an LL4 ordinary chondrite and appears in the Meteoritical Bulletin Database. You can verify this classification at the Meteoritical Bulletin entry for NWA 17707. This specimen includes a certificate of authenticity documenting its classification and provenance.

What does LL4 mean? The first L indicates low total iron content, the second L means low metallic iron specifically, and 4 represents the petrologic type indicating moderate thermal metamorphism. This combination describes both composition and thermal history.

What is included with this specimen? You receive the 30.37g meteorite slice and a certificate of authenticity. No display stand is included unless specifically noted in the product images.

Why are chondrules important? Chondrules are the oldest processed materials in the solar system, frozen droplets that formed when dust melted and rapidly cooled in the solar nebula. Their presence proves this meteorite has not been significantly melted since that time, preserving a direct sample of pre-planetary material.

Collector significance

Full slices expose interior structure that exterior fragments cannot show. This specimen presents chondrules across its entire face, offering more visual interest than partial sections or fragments where primitive features may be limited to small areas. The 30.37g size provides substantial display presence while remaining accessible compared to larger examples.

The 2024 classification makes this a recent addition to the meteorite catalog. Collectors seeking current finds with fresh documentation will find NWA 17707 fits that category. The LL classification is less common than H chondrites in the NWA series, adding compositional diversity to collections focused on ordinary chondrite varieties. Browse additional examples in our Chondrites collection to compare LL, L, and H types side by side.

Meteoritical Bulletin entry: NWA 17707 | Classification: Ordinary Chondrite (LL4) | Find, Algeria, 2024