AN ANALYSIS OF NWA 8632

As part of a class project and to learn about different mineral identification techniques, the WCU Minerology class examined the composition of pyroxene grains within Northwest Africa (NWA) 8632, a lunar mare basaltic meteorite. The sample was first examined optically at WCU using plane- and cross-polarized light, as well as using Back Scattered Electron images and X-ray elemental maps generated at Rutgers University using the JEOL JXA 8200 Superprobe to select analysis points. The major and minor elements were quantified using the Cameca SX 100 electron microprobe (EMP) housed in the Dept. of Earth and Planetary Sciences at the University of Tennessee, Knoxville. Our data shows that the Pyroxene grains are predominantly augite, with few pigeonites; overall, cores were more Mg-rich than the rims, as expected. The bulk composition of NWA 8632 has been shown to be similar to lunar mare basaltic meteorite NWA 032, although the two stones are not considered to be paired; despite this bulk composition similarity, the pyroxene grains in NWA 8632 tend to be more Fe-rich than those found in NWA 032.