Effects of compositional variation on absorption spectra of lunar pyroxenesPolarized absorption spectra of lunar pyroxenes with a range of iron, calcium, magnesium, titanium and chromium contents were measured on polished, oriented single crystals; spectral data on pure synthetic FeSiO3 were also recorded. The bands at 1 and 2 microns were found to vary significantly in position with composition within the pyroxene quadrilateral; wavelengths increased with increasing calcium and iron. In the visible region, a weak band at 640 nm correlates in intensity with Cr2O3, but not with titanium as had been previously suggested. The 505-nm ferrous iron peak is a sharp doublet in most low-calcium pyroxenes but a singlet in augites. A peak at 475 nm and an intense absorption edge below 700 nm correlated with titanium content.
Document ID
19790055247
Acquisition Source
Legacy CDMS
Document Type
Conference Proceedings
Authors
Hazen, R. M. (Carnegie Institution of Washington Washington, DC, United States)
Bell, P. M. (Carnegie Institution of Washington Washington, DC, United States)
Mao, H. K. (Carnegie Institution of Washington Washington, D.C., United States)