Zhob, Rare H3-4 Pakistan Hammer Fall, January 2020, Micromount

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On January 09, 2020, a bright fireball appeared in the late afternoon skies over the Baluchistan region of Pakistan. A serious of loud sonic booms followed the fireball across the sky. The meteor dropped a handful of stones, each weighing a few kilos or more. One stone crashed through the roof of a house in the Zhob district of the Mando Khel tribal area. Brokers acquired some of the stones and they were acquired by US meteorite dealers who had the stones analyzed by Dr. Garvie at the University of Arizona. The meteorite was classified as a rare H3-4 type, which is a breccia of type-4 clasts set into a type-3 matrix. Zhob is only the second known fall of this type and the first in over 100 years, so scientists are quite excited to study it.

Very little of this meteorite is available on the collector market and the majority of that is large expensive pieces. For collectors, this is a trifecta meteorite : witnessed fall, hammer fall, and a rare type (one of only 18 known H3-4 chondrites and only the second fall). In addition, meteorites from Pakistan are hard to come by in general.

Refer to the photo. The black centimeter cube is shown for scale and is not included. You are purchasing a single small fragment like the one shown. Your purchase will include a labeled gemjar for safe storage.

From the Meteoritical Bulletin entry on Zhob :

Zhob        31°22’N, 69°34’E

Baluchistan, Pakistan

Confirmed fall: 2020 Jan 9

Classification: Ordinary chondrite (H3-4)

History: (M. Farmer, Arizona) A bright fireball followed by sonic booms was seen and heard around the northern part of the Baluchistan province of Pakistan, approximately 6:30 pm local time on 9 January 2020. Shortly thereafter, a stone fell through a house in a local village of the Mando Khel tribal area ~12 km NE of Zhob, Zhob District, Baluchistan province, Pakistan. The largest stone was found shortly after the fall by goat herders. Two more stones were subsequently found in this area.

Physical characteristics: To date, four fusion-crusted stones have been found: 6.309, ~5.5, 4.924, and 2.231 kg. The stones are blocky to rounded, with broad shallow regmaglypts, and covered with black matte fusion crust. The 6.309 kg stone is broken, exposing ~15 × 9 cm of the interior, which displays a breccia of rounded to sub-rounded, light-colored clasts in a light-gray matrix. The clasts range from 1 cm to 5 × 4 cm. The stone is easy to break and weakly consolidated. The measured density of a 24 g fragment that contains both the lithologies is 3.18 g/cm3.

Petrography: (L. Garvie, ASU) The exposed surface of the 6.309 kg stone has an earthy luster, with scattered small (<1 mm) chondrules and rare troilite fragments to 4 mm. No shock veins are visible. Two polished mounts were examined from the gray matrix and a large light-colored clast, respectively. Gray matrix: Section dominated by chondrules and chondrule fragments set in a fine-grained fragmental matrix. Chondrules abundant and clearly visible under a petrographic microscope and BSE imaging, with an apparent mean diameter of 460 µm (n=36). Some PO and PP chondrules show phenocrysts with clear zoning. A PO and BO chondrule contains transparent purple glass. Fe-Ni metal dominated by two grain types: the first is irregularly shaped, with holly-leaf-shaped outlines, to 200 µm grains of kamacite that are single crystals exhibiting weakly developed Neumann bands; the second are rounded grains up to 150 µm, with thin taenite rims enclosing cores of dark-etching plessite. Native copper is rare occurring as grains to 20 µm between Fe-Ni metals and troilite. Troilite grains to 150 µm are largely single crystals and lack shock lamellae. Chromite is a common accessory mineral, occurring as anhedral grains to 200 µm and as fine-grained chondrule-like aggregates to 300 mm. Light-colored clast: The petrography and chondrule size in this clast is similar to the gray matrix section, but differs in showing a coarser grained matrix with abundant feldspathic phase up to 20 µm, and lacking chondrules with zoned olivine or pyroxene-bearing phenocrysts.

Geochemistry: (A. Wittmann, L. Garvie, ASU) Gray matrix - Olivine (n=23) Fa17.2±6.6, range Fa0.7-34.3, Cr2O3 to 1.2 wt% and CaO to 0.5 wt%. FeO/MnO = 38.6±7.9. Low-Ca pyroxene (n=20) Fs13.8±5.3Wo1.3±1.1, FeO/MnO = 25.1±10.3. High-Ca pyroxene (n=2) Fs1.1Ca45.9 and Fs24.2Ca30.5. Light-colored clast - Olivine (n=14) Fa18.5±0.24, range Fa17.9-18.8, FeO/MnO = 37.8. Low-Ca pyroxene (n=17) Fs15.3±0.3Wo1.3±0.1, FeO/MnO = 23.4. Kamacite: Ni 6.71-7.08 wt%, Co 0.44-0.48 wt%. Feldspathic phase (stoichiometry is poor, FeO is fairly high): Ab81.4-83.1An10.7-12.6Or4.3-6.5 (n=10).

Classification: H3-4. Breccia of H4 clasts in an unequilibrated H3 host matrix. W0 and S2.