Gyarub Zangbo Pallasite Meteorite Slice, Ungrouped Pallasite, 74.92g, Tibet

Gyarub Zangbo Pallasite Meteorite Slice, Ungrouped Pallasite, 74.92g, TibetBacklit translucent olivine in a rare ungrouped Tibetan pallasite This slice of Gyarub Zangbo is not a typical pallasite. Geochemical analysis of its olivine and metallic phases, combined with oxygen and chromium isotope data, confirms that Gyarub Zangbo originated from a parent body distinct from all other known pallasites. It is classified as an ungrouped pallasite, a designation confirmed by the Meteoritical Society in MB 114 (April 2026) that

Backlit translucent olivine in a rare ungrouped Tibetan pallasite

This slice of Gyarub Zangbo is not a typical pallasite. Geochemical analysis of its olivine and metallic phases, combined with oxygen and chromium isotope data, confirms that Gyarub Zangbo originated from a parent body distinct from all other known pallasites. It is classified as an ungrouped pallasite, a designation confirmed by the Meteoritical Society in MB 114 (April 2026) that places it outside all established pallasite groups.

When this 74.92g slice is held to a light source, sections of the olivine come alive in warm amber and honey tones, while neighboring crystals stay dark olive-green or nearly black from terrestrial weathering. The contrast between the two states is striking. Polished iron-nickel metal flows between the crystals with a soft mirror finish, and the Widmanstatten structure is visible where etching reaches the metal margins. A thin protective epoxy coating sealed on both faces keeps the olivine stable and limits ongoing oxidation.

Structure and features

Gyarub Zangbo's olivine fayalite content is Fa21.6-22.8 mol%, slightly higher than typical main group pallasites and consistent with its ungrouped status. The metallic component contains approximately 15.8% nickel, also elevated relative to most main group pallasites, and trace amounts of cobalt, copper, and germanium that further distinguish it from the PMG parent body.

Olivine grains in this 74.92g slice range from fine sub-millimeter inclusions up to centimeter-scale aggregates, spread irregularly through the polished face. Concentrated crystal-rich zones sit next to broader stretches of exposed iron-nickel metal, creating a varied internal pattern across the slice. Along part of the perimeter, an unpolished natural edge preserves the weathered crust of the original stone, with surface oxidation that records its long exposure on the Qinghai-Tibet Plateau.

Discovery and provenance

Gyarub Zangbo was discovered in October 2020 by Mr. Tulga during exploration of the uninhabited Qiangtang region of the Qinghai-Tibet Plateau, northeast of the Gyarub Zangbo River in Tibet, China. The find comprised disaggregated olivine and metal fragments scattered across the surface, along with a larger metal-rich mass nearby. The total recovered weight was approximately 17.6 kilograms, making Gyarub Zangbo one of the rarest pallasites available to collectors by total known weight.

The remote plateau environment preserved the specimens from human disturbance while subjecting them to high-altitude weathering. The result is a pallasite with significant surface oxidation on natural faces but excellent interior preservation where the polished slice reveals the original olivine-metal structure. Learn more about this meteorite type: What Is a Pallasite?

Scientific context

The ungrouped classification of Gyarub Zangbo is its most scientifically significant attribute. Main group pallasites, the most common type, including Sericho, Esquel, and Brenham,  share a common parent body linked to the IIIAB iron meteorite group. Gyarub Zangbo does not. Its oxygen isotopic signatures plot along an array between PMG and Eagle Station pallasite values but do not overlap with any other known ungrouped pallasites. The metal composition shows affinity with IIF irons rather than the IIIAB irons linked to the main group, and nickel content is elevated above both Eagle Station and PMG values. These data collectively confirm a parent body distinct from all established pallasite groups.

This makes Gyarub Zangbo a window into a differentiated parent body not represented by any other pallasite in collections. The reclassification to ungrouped in MB 114 (revised April 2026) reflects the current official classification. A 2023 paper by Jiang et al. presented at the 54th Lunar and Planetary Science Conference proposed that Gyarub Zangbo may have carbonaceous origins consistent with formation beyond Jupiter's orbit, based on its oxygen isotope array and olivine chemistry. While this interpretation has not been incorporated into the official Meteoritical Bulletin classification, it represents active scientific inquiry that adds a layer of interest few other pallasites can claim. Browse our Stony-Iron Meteorites collection for related specimens.

Frequently asked questions

Is this meteorite authenticated? Yes. Gyarub Zangbo is an officially classified meteorite. See the official Meteoritical Bulletin entry for Gyarub Zangbo. This specimen ships with a Treasure Coast Meteorite Co. certificate of authenticity. Offered by Treasure Coast Meteorite Co., IMCA #3323.

What makes Gyarub Zangbo different from other pallasites? Most pallasites belong to the main group (PMG) and share a single parent body. Gyarub Zangbo is classified as ungrouped (confirmed in MB 114, April 2026) because its olivine chemistry, nickel content, and oxygen isotope ratios do not match the PMG, Eagle Station group, or any other established pallasite group. Its metal shows affinity with IIF irons rather than IIIAB, placing its parent body outside the known pallasite family tree.

Why does the olivine glow when held to light? Fresh pallasite olivine is transparent to translucent, and many crystals in this specimen retain enough translucency to transmit light. The amber and orange glow visible when the slice is backlit is the natural color of the olivine itself, the same mineral as the gemstone peridot. Terrestrial weathering gradually makes olivine opaque, but Gyarub Zangbo's relatively recent discovery means many crystals preserve this optical quality.

What does the epoxy coating do? The thin epoxy applied to both faces stabilizes the olivine crystals and slows further terrestrialization, the oxidation process that gradually darkens and opacifies the olivine. It does not affect the visual quality of the specimen and is standard practice for pallasite preservation.

What is included? The polished slice shown, on an acrylic display stand, with a Treasure Coast Meteorite Co. certificate of authenticity. This slice carries a thin protective epoxy coating on both faces.

Collector significance

At 17.6 kilograms total known weight, Gyarub Zangbo is among the rarest pallasites by total mass, rarer than Fukang, rarer than most named pallasites in collector circulation. Its anomalous classification adds scientific significance beyond simple rarity: this is a meteorite from a parent body not represented by any other known specimen. For collectors building a serious pallasite collection or a scientifically representative stony-iron suite, Gyarub Zangbo occupies a category that no other available specimen can fill. The backlit olivine quality in this lot is exceptional for a specimen of this age and exposure history.

Meteoritical Bulletin entry: Gyarub Zangbo | Classification: Pallasite (ungrouped) | Find, Xizang, China, 2020 | Total known weight: 17.61kg | MB 110 (2022), revised MB 114 (2026)

Learn more about Gyarub Zangbo: origin, classification, and science