METHOD AND APPARATUS FOR DETERMINING THE COLOR OR CUT DIAMONDS

摘要

The diamond is held by a well known holder below its holder or mounting edge leaving its upper portion with the planar surface and the facets fully exposed. A light ray of a predetermined wave length entering the diamond through the upper planar surface is totally reflected within the diamond in accordance with the geometric configuration of rays and emerging from the facets of the diamond. The amount of attenuation between the entering and the emerging light ray is measured photoelectrically, whereby attenuations of the entering light ray caused by surface reflections and by varying adjustments of the diamond are avoided.