The Moon problems of mineral mixtures

The close proximity of the Moon to Earth and its lack of an atmosphere have resulted in the compilation of a large number of telescopic reflectance spectra 

The ultimate objective of remote reflectance spectral measurements is to obtain quantitative estimates of the modal mineralogy of unexplored surfaces of the Moon and, indeed, other terrestrial planets. This necessitates difficult and elaborate spectrum-curve fitting procedures, which has been the focus of detailed research (e.g., Roush and Singer, 1986 Clouds et al., 1986 Mustard 

Troctolite is thus believed to be the major rock-type forming the central peaks of Copernicus. Reflectance spectra of rays emanating from Copernicus contain more calcic-rich pyroxenes indicative of pigeonite-augite assemblages (Pieters etal., 1985). 

---