Sinawan 005 Rumuruti Meteorite Individual, R5-6, 14.49g, Dual Lithology R-Chondrite

Dual lithology R-chondrite from Libya

This 14.49g Sinawan 005 individual preserves two distinct lithological zones across its natural surface -- a light-toned region and a contrasting dark zone that meet in a sharp boundary. The specimen retains partial fusion crust on one face, evidence of atmospheric entry. Rumuruti chondrites represent less than 0.5% of all classified meteorites, making this R5-6 specimen from a recent 2023 Libyan find scientifically significant.

The dual lithology structure visible in this piece reflects differing thermal or shock histories within the parent body before ejection. R-chondrites are named after the Rumuruti fall in Kenya and characterized by oxidized, fine-grained matrices with distinctive olivine compositions. Only three specimens of Sinawan 005 are known to exist.

Structure and features

The light zone shows tightly packed chondrules embedded in a fine matrix, typical of the R5-6 petrologic type. The darker region displays a more opaque matrix with less visible chondrule definition, suggesting localized shock darkening or impact melt influence. The contact between these zones runs diagonally across the specimen face, creating a natural contrast that highlights the meteorite's complex formation environment.

Partial fusion crust covers approximately 30% of the surface, preserving the black glassy rind formed during atmospheric passage. The exposed interior reveals the characteristic rust-brown coloration of oxidized R-chondrite material. No regmaglypts are visible on this small individual, but the fusion crust shows smooth flow textures consistent with rapid melting and cooling.

Scientific context

Rumuruti chondrites formed in an oxygen-rich region of the early solar system distinct from ordinary and carbonaceous chondrite parent bodies. The R-chondrite parent body remains unidentified, though spectroscopic studies suggest possible links to certain asteroids in the outer main belt. The R5-6 classification indicates this specimen experienced moderate thermal metamorphism, reaching temperatures sufficient to recrystallize silicates while preserving recognizable chondrules.

The dual lithology in this specimen records either impact brecciation or distinct cooling zones within the parent asteroid. Such features provide critical data about impact processing and thermal gradients in small planetary bodies. Researchers study R-chondrites to understand oxygen isotope distributions and oxidation states across different nebular regions. For broader context on meteorite classification systems, see our Learn About Meteorites guide.

Frequently asked questions

Is this meteorite authenticated? Yes. Sinawan 005 is classified as Rumuruti (R5-6) in the Meteoritical Bulletin. You can verify this classification through the MetBull database. This specimen includes a certificate of authenticity documenting its provenance and classification.

What does dual lithology mean? Dual lithology indicates two distinct rock types or structural zones present in a single meteorite specimen. In this Sinawan 005 piece, the light and dark zones represent different mineral assemblages or shock states that formed in the parent body before the meteorite reached Earth.

What is included with this specimen? You receive the 14.49g Sinawan 005 individual and a certificate of authenticity. No display stand is included.

Why are only three specimens of Sinawan 005 known? Sinawan 005 represents an extremely limited recovery from the 2023 find in Libya. The total known weight is minimal, and only three individual stones were classified and distributed. This scarcity makes each specimen scientifically valuable and highly collectible.

Can I display this meteorite without a case? R-chondrites are stable at room temperature and do not require sealed storage like hygroscopic carbonaceous chondrites. The fusion crust and oxidized matrix are durable. Standard display conditions away from prolonged moisture exposure are sufficient.

Collector significance

Sinawan 005 joins fewer than 100 classified Rumuruti chondrites worldwide. The R-group represents the rarest chondrite family available to private collectors. This 14.49g individual offers dual lithology structure visible without magnification, combining scientific interest with display appeal. Only three specimens exist, making acquisition opportunities extremely limited.

The specimen's natural surface and partial fusion crust provide authentication markers that distinguish it from processed slices. For collectors building reference sets of rare chondrite types, this Sinawan 005 individual fills a critical gap. Explore other rare chondrite specimens in our Chondrites collection.

Meteoritical Bulletin entry: Sinawan 005 | Classification: Rumuruti (R5-6) | Find, Libya, 2023