Gyarub Zangbo Pallasite Meteorite Slice, Ungrouped Pallasite, 301.28g, Tibet

A 301.28g slice of Gyarub Zangbo, an ungrouped pallasite from Tibet

This is a 301.28 gram polished slice of Gyarub Zangbo, a pallasite recovered from the Qinghai-Tibet Plateau. Olivine sits in clustered fields across a bright iron-nickel matrix that has been etched to reveal the crystal structure of the metal. Gyarub Zangbo is not a main group pallasite. The Meteoritical Society revised its classification to Pallasite, ungrouped in Meteoritical Bulletin 114, published in 2026, and as of August 2026 it is 1 of 17 approved meteorites carrying that classification. For background on the type, see our guide on what a pallasite is. The photographs show the exact specimen offered.

Structure and features of this slice

The polished faces carry olivine in irregular clusters rather than an even scatter, with the largest groups running to several centimetres across and isolated grains elsewhere in the field. Where the crystals remain translucent they transmit amber and honey tones under strong light; weathered grains stay deep brown to near black. Both faces are photographed here, and the olivine distribution differs between them, which is what you would expect from a slice cut through a coarse aggregate.

The metal takes a fine crosshatched etch pattern across both faces, the intergrowth of kamacite and taenite that the Bulletin records as the metal phases in this meteorite. The Bulletin describes Gyarub Zangbo as a coarse grained aggregate with a mean grain size of about 5 mm and a simple mineralogy of olivine and metal.

Published geochemistry: olivine Fa21.6±0.4 with Fe/Mn 66.9±3.9 (n=41). The reclassification work added orthopyroxene Fs19.1±2.3Wo2.0±0.8 (N=21), augite Fs8.2±0.4Wo43.0±1.6 (N=6), and two populations of chromite, alongside troilite, schreibersite and the phosphates stanfieldite and farringtonite. The Bulletin records a shock stage of low and a weathering grade of low.

This slice carries a thin protective epoxy on the polished faces. The coating stabilizes the olivine and slows oxidation, and is standard practice for pallasite preservation.

Discovery and provenance

Gyarub Zangbo was found in October 2020 by G. Tulga during exploration of the uninhabited Qiangtang region of the Qinghai-Tibet Plateau, northeast of the Gyarub Zangbo river in Xizang, China, at 33.126°N, 87.079°E. The recovery consisted of many disaggregated fragments of olivine and metal together with a larger metal-rich mass found nearby. All of the material was purchased by Ziyao Wang in October and November 2020, and the Bulletin records the main mass as being with him.

The type specimen, 120 g including two polished end cuts, is held at the Burke Museum of Natural History and Culture at the University of Washington. Classification was carried out by A. Irving at the University of Washington and P. Carpenter at Washington University in St. Louis, approved 13 March 2021 and submitted by A. Irving. The working names recorded in the Bulletin are WZY-01 and WZY-10. This specimen was acquired by Treasure Coast Meteorite Co.

The Bulletin indexes a mass of 17.61 kg from the original MB 110 entry. The MB 114 reclassification writeup states that the updated total mass is now more than 200 kg, so the indexed figure reflects only the material described in the first announcement. Browse related specimens in our Stony-Iron Meteorites collection.

Scientific context

The ungrouped classification is the most scientifically interesting thing about this meteorite. Most pallasites belong to the main group, which shares a parent body tied to the IIIAB irons. Gyarub Zangbo does not fit there, and it does not fit the Eagle Station group either.

The reasoning is set out in the Bulletin. Its olivine is close in composition to Eagle Station pallasites but carries lower Fe/Mn ratios, and is clearly distinct from main group olivine. It contains pyroxene, a phase absent from both the main group and the Eagle Station group. Its oxygen isotopes plot on an array between main group and Eagle Station values without overlapping any other ungrouped pallasite. Its metal shows affinity with the IIF irons rather than the IIIAB irons, and its nickel content is higher than that of the IVB irons, the Eagle Station pallasites and the main group. Taken together these point to a parent body represented by no other pallasite in collections.

Two studies presented at the 54th Lunar and Planetary Science Conference in 2023 developed this further. Jiang and colleagues characterised Gyarub Zangbo as an anomalous carbonaceous pallasite, placing it in the carbonaceous reservoir, the population of material understood to have formed outside the orbit of Jupiter rather than in the inner solar system where most meteorite groups originate. Boesenberg and colleagues, in a study of new pyroxene pallasites and the number of pallasite parent bodies, treated it as evidence that pallasites come from considerably more parent bodies than once assumed.

Both are conference abstracts representing active research rather than settled classification, and neither forms part of the official Meteoritical Bulletin entry. Stated with that caveat, they make this an unusually interesting pallasite: a stony-iron that may record a body assembled beyond Jupiter. Further reading is on our Gyarub Zangbo origin and science page.

Frequently asked questions

Is this meteorite officially classified? Yes. Gyarub Zangbo is an officially named meteorite, announced as a pallasite in Meteoritical Bulletin 110 (2022) and revised to Pallasite, ungrouped in Meteoritical Bulletin 114 (2026). Offered by Treasure Coast Meteorite Co., IMCA #3323.

What makes Gyarub Zangbo different from other pallasites? Most pallasites belong to the main group and share one parent body linked to the IIIAB irons. Gyarub Zangbo matches no established group: its olivine chemistry, nickel content, oxygen isotopes and IIF metal affinity all separate it, and it carries pyroxene that the main group and Eagle Station group lack.

What is the carbonaceous connection? A 2023 study by Jiang and colleagues characterised Gyarub Zangbo as an anomalous carbonaceous pallasite. Material in the carbonaceous reservoir is understood to have formed outside the orbit of Jupiter, which would place this meteorite's parent body in the outer solar system. That interpretation comes from conference research and is not part of the official Bulletin classification.

Why does the olivine glow when held to light? Fresh pallasite olivine is transparent to translucent, and many crystals in this slice still transmit light. The amber and gold seen when backlit is the natural colour of olivine, the same mineral as the gemstone peridot. Weathering gradually turns olivine opaque.

What does the epoxy coating do? A thin epoxy on the polished faces stabilizes the olivine and slows the oxidation that darkens the crystals over time. It does not change the visual quality of the slice and is standard practice for pallasite preservation.

How scarce is this classification? As of August 2026 the Meteoritical Bulletin database records 17 approved meteorites classified as Pallasite, ungrouped.

Collector significance

At 301.28 grams this is a display slice rather than a study piece, large enough to carry both faces of a coarse pallasite structure with room for the olivine clusters to read at a distance. It combines that scale with a classification shared by only 17 approved meteorites as of August 2026, and with an active research case that its parent body formed beyond Jupiter.

This specimen carries serial TC-00035 in the Treasure Coast Meteorite Co. specimen record programme. Its permanent record, with identification data, provenance and photographs, is at Specimen Record TC-00035, and the full index is on the specimen registry.

Meteoritical Bulletin entry: Gyarub Zangbo | Classification: Pallasite, ungrouped | Find, Xizang, China, October 2020 | MB 110 (2022), reclassified MB 114 (2026) | IMCA #3323