From the Website of Ocean Optics, an applications note for their Jaz Spectrometer
“Reflectance spectroscopy is a versatile technique than can be used to identify and characterize a range of powdered samples including mineral powders, grains in lunar samples, mining samples, natural deposits, soils and sediment core samples. In this application note, reflectance spectroscopy is used to characterize mineral powder samples.
“The Jaz spectrometer was used to acquire reflectance spectra for pure samples and powder mixtures to assess the power of reflectance spectroscopy to characterize mineral powder samples.”
Since a Normal spectral reflectance method can provide a good estimate for the Normal spectral emissivity or emittance of an object, especially an opaque one, this measurement method can be a valuable resource in the characterization of the shape of the Normal Spectral Emissivity Vs. Wavelength curve of specific materials, if not a reasonable estimate of its room temperature spectral emissivity values, with appropriate geometry corrections, over a limited range of wavelengths.
The complete, free technical article is located on the Ocean Optics website at: http://oceanopticsfaq.com/apps/chemistry/reflectivity-of-mineral-powders/
It can be converted to pdf format and then downloaded at: http://en.pdf24.org/