One of the most interesting discoveries we made at Tucson this year was, in our experience, a unique method of fashioning cultured pearls. Komatsu Diamond Industry of Kofu City, Yamanashi, Japan, is faceting Tahitian, South Sea, freshwater, and mabe cultured pearls. The finished products are being marketed as 'Komatsu Flower Pearls.' According to Komatsu literature, the company is using a faceting technique that was developed in 1992 by Kazuo Komatsu, who was trained as a diamond cutter. Since it would be undesirable to cut through to the shell bead, the cultured pearls selected for this technique must have thick nacre layers. Each fashioned pearl has 108-172 facets and should only require the same care as for more typical cultured pearls, according to Komatsu. However, the manufacturer cautions against polishing mounted 'Komatsu Flower Pearls' with a buffer.

We examined 10 of these cultured pearls. The faceting produces a very curious optical effect: All of the facets appear to be distinctly convex. However, closer inspection with a microscope and reflected light showed that the facets were indeed flat. The curved effect is apparently produced by the flat facets cutting through the numerous individual curved layers of nacre, bringing deep nacre layers closer to the surface in the middle of the facets. In some cases, remnants of the original surface can be seen between facets.

Appears on pages 146-147

Photo GIA