OPTICAL-PROPERTIES OF CALCITE AND GYPSUM IN CRYSTALLINE AND POWDERED FORM IN THE INFRARED AND FAR-INFRARED

The complex indices of refraction for crystalline gypsum and calcite w ere determined from reflectance measurements for both single crystals and pressed powder pellets. These optical constants were determined fr om a classical dispersive analysis (DA) of the reflectance data to fac ilitate comparisons between the crystal and powdered data. This study was done to show the usefulness and the limitations of using pressed p ellets for determining the complex refractive index of materials unava ilable in single crystals.