jade, jadeite, fei cui, nephrite, gems, Fischer-Book, Broken Bangle

IN the Journal" for April, 1952, I described an easy photo-Igraphic method whereby the refractive index of faceted gemstones could b e closely estimated and their size, shape, and facet distribution permanently recorded, without the use of a camera. Briefly, the process consisted in immersing the stones in a glass cell containing a suitable liquid, then, in the dark, sliding under the cell a sheet of printing paper or flat film, and exposing for a few seconds to light from a n overhead lamp. After development, the contact print so produced showed very clear, indeed one might say spectacular, differences in the appearance of the stones according to their refractive indices in relation to that of the liquid."