Classification: Achondrite Diogenite, anomalous, S-low, W-low
Place/Time: 2024 in Libya
Mass: 2kg
History: The meteorite was purchased from a meteorite dealer in Libya.
Physical characteristics: Light grayish to light greenish stone partly covered with patchy fusion crust.
Petrography: Achondrite dominantly composed of a fine-grained lithology with interspersed coarse-grained enclaves. In the fine-grained part patchily zoned pyroxenes and calcic plagioclase are the most abundant mineral phases. Both are often lath-shaped and gradually coarsen radially towards the enclaves which are dominantly composed of blocky up to 4 mm sized low-Ca pyroxene crystals. Many of these large crystals show resorption textures with embayed outlines and are sometimes overgrown by more Ca-rich patchy pyroxene. Olivine is a minor constituent in the fine-grained regions but becomes more abundant and more ferroan towards the coarse-grained areas. In both lithologies olivine often contains trapped melt inclusions and myrmekitic intergrowths of low-Ca pyroxene and troilite. Vesicles are abundant in the fine-grained regions. Minor phases include silica, apatite, chromite, troilite, and FeNi metal.
Geochemistry: fine-grained lithology: patchily zoned pyroxene: Fs35.0±14.0Wo10.2±7.9 (Fs20.1-66.0Wo1.0-25.0, FeO/MnO=24-36, n=20); olivine: Fa31.3±0.6 (Fa30.5-32.1, FeO/MnO=44±2, n=10); calcic plagioclase: An90.6±1.5Or0.5±0.2 (An87.3-91.7Or0.3-0.9, n=10); Cr# in chromite: 68.4±3.1, n=5; coarse-grained lithology: olivine: Fa45.1±6.9 (Fa33.9-53.1, FeO/MnO=43±3, n=10); large low Ca-pyroxenes: Fs25.6±0.9Wo2.4±0.5 (Fs24.2-27.1Wo1.4-3.3, FeO/MnO=24-29, n=12); exsolutions in large pyroxenes: Fs28.3±1.0Wo5.5±0.3 (Fs26.4-29.0Wo5.0-5.9, FeO/MnO=25-29, n=6)
Classification: Diogenite (anomalous, olivine-bearing). Diogenite based on presence of large low-Ca pyroxene grains, FeO/MnO ratios of pyroxene and olivine, and An-content of plagioclase. Anomalous designation based on dominant fine-grained lithology with abundant patchily zoned pyroxenes.
1 of 12 Diogenite-an and 2nd largest and best looking one !!!
Specimen mirror polished on one side.
