Collection
Classification: L6 (Low iron), Brecciated
Observed fall: No
Year found: 2019
City, Country: Northwest Africa
Mass: 607 g
In collection
Weight #1 : 3,83 g
Certificate of authenticity: Yes (1)
NWA 12845 is classified as an L6 ordinary chondrite, meaning it has relatively low iron (L) content compared to H chondrites and has experienced extensive thermal metamorphism (type 6). Discovered in Northwest Africa, this meteorite has a highly equilibrated, recrystallized texture in which the original chondrule outlines are largely erased. Its silicate minerals—mainly olivine and pyroxene—show uniform compositions, while the abundance of metallic iron-nickel and sulfides is modest, consistent with the “L” subgroup. Studying NWA 12845 provides insights into the heating and metamorphic processes that occurred on its parent asteroid, transforming the once-primitive chondritic material into a thoroughly homogenized rock.
When examining a thin section of NWA 12845 – an L6 ordinary chondrite under a light microscope, you’ll notice that original chondrule boundaries have been almost completely obliterated by thermal metamorphism. Instead, the sample presents a uniform, granoblastic texture dominated by equilibrated olivine and pyroxene crystals, each displaying stable interference colors under polarized light. Small, opaque metallic iron-nickel and sulfide grains appear as scattered reflective inclusions, consistent with the “low iron” classification. Occasional microfractures or subtle shock features may be visible, but overall the sample shows the hallmarks of a thoroughly metamorphosed rock with minimal evidence of its once-distinct chondrules.
