Eye-witness meteorite specimens that bring together a variety of molten shell features
International naming: Hammadam Hamra
346 (HaH 346) 29°36'29.3"N, 13°22'03.4"E
Galian, Libya
Fall time: 2018
Category: Common Chondrites (L6)
History: On August 26, 2018, a large fireball was widely seen and heard in the sparsely populated area of the southern Gabir Mountain region of Libya. In early 2019, Mr Belal found hundreds of newly fusion-cured stones, weighing more than 100 kilograms, about 95 kilometers southwest of Ash Shuwayrif, scattered over several kilometers. S. Omar Aliby (and other meteorite hunters) visited the site. The molten crust is fresh, matte black, and lacks evidence of extensive wind wear. Given that these stones are completely completely unventilated, they may have originated from the 2018 meteors seen in the region. In 2019, Mr. Marcin Cimala purchased 30 kilograms of this material from a meteorite dealer in Mauritania. This potentially depraved stone is currently being traded in the name of Ghadamis.
Physical properties: Many individuals range from about 100 grams to a few kilograms, and most of the unbroken stones are covered by matte black fusion crust. Many stones show well-developed shallow regmaglypts. Overall, the stones are blocky. In places where fusion is lacking, meteorites show a light gray interior. The specimen is very fresh; Some show a very slight brown exposure metal stain.
Petrology: (A. Greshake， MNB; L. Garvie, ASU) meteorites show a recrystallization texture consisting mainly of constituent equilibrium olivine and low-calcium pyroxene particles, showing triple junctions of 120 degrees in some areas. There are few flat and delineated PO, BO (up to 1 mm) and porous PP pellets. The matrix contains plagioclase, chromite, spessartine garnet, diorite, cadmium and potassium feldspar. Plagioite grain size is approximately 60 μm. Shock melt veins are rare, but are locally present in pockets. Fe-Ni metal and diorite are evenly distributed in the polished section. The largest iron-nickel grain diameter is about 1 mm. Most pyrite particles are polycrystalline and contain finely dispersed, submicron-sized meteorites. Some show complex metal-sulfide eutectic intergenesis. Some of the larger karmal grains show icy etching and weakly developed Neumann belts. Trojan, 0.5 mm in diameter, is highly vibrating, polycrystalline, and has a dusty appearance. Copper metal was searched but not found.
Geochemistry: (A. Greshake, MNB) Peridot: Fa23.8±0.3 (Fa23.1-24.2, n=12), Low Calcium Pyroxene: Fs20.2±0.3Wo1.6±0.2 (Fs19.7-20.9Wo1.2-2.0, n=12), Feldspar: An11.2±0.7Ab84.4±1.1Or4.4±0.6 (An10.7-12.4Ab82.8-85.4Or3.7-5.3, n= 4）
Classification: Common chondrite meteorites L6, S5, W0
Specimen: 200 grams for MNB and 325 grams for Arizona State University.
