Figure 7
From: Gigapixel optical microscopy for meteorite characterization
GRO 95577 meteorite thin section. Reflected light optical micrographs of CR1 chondrite GRO 95577. Brighter materials in reflected light tend to be metal or opaque minerals such as oxides and sulfides. At low magnification (top) we can see that the opaque minerals are mostly fine-grained and scattered thoroughly about the groundmass, an indication that this meteorite has experienced heavy aqueous alteration. Higher magnification (bottom) reveals zoning in magnetite (an iron oxide), due to variation in chemical composition. Such zoning indicates that the mineral grew in a disequilibrium setting.