Natural-color saltwater cultured pearls from Pinctada margaritifera were studied by diffuse reflectance UV-Vis-NIR spectroscopy to identify the absorption features associated with their various colors ...
Figure 1. This 239.25 ct topaz crystal hosts some interesting inclusions of ferrocolumbite. Photo by Diego Sanchez. The author recently acquired a 239.25 ct transparent well-formed topaz crystal from ...