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complementary realities. Gemstones react to sun rays in a diametrically opposed way, depending on their clarity or original obscurity. If white, in short achromatic, they reflect all the wave lengths of the visible light, if black they absorb all the wavelengths of the light and are outwardly devoid of it. These characteristics have a decisive influence on the identification of internal inclusions, not visible in black gems, and on the contrary, easy to observe in white transparent gems. In the case of white diamonds, the degree of purity is essential: the purity and the cut of white gemstones affect their brilliance, which is enhanced by the round brilliant cut also called “diamond cut” because it was developed to highlight the brilliance of the white diamond. It is important to
understand the type of gem before examining a white transparent gem and not expect coloured gems classified VS to have the same look of white VS diamonds. For example, quartz, sapphire and zirconium are type II gems and usually have minor inclusions, while topaz is a type I gem, which is usually clean to the naked eye. Some gemstones are found in both the black and white varieties or can also be white and black in the same precious gem. One of these is onyx, a variety of white and black striped agate, used in ancient Rome for glyptic. Jade is
In alto: orecchini pendenti in diamanti bianchi e neri taglio circolare, oro bianco 18 Kt. Firmati Chantecler, circa 2000. Sopra: orecchini “Rose de Noël”, a forma di fiore, con petali in onice, diamanti taglio circolare, oro giallo. Firmati Van Cleef&Arpels.
Top: drop earrings in white and black circular cut diamonds, 18 Kt white gold. Signed Chantecler, approx.2000. Above: flower-shaped “Rose de Noël” earrings, with petals in onyx, circular cut diamonds, yellow gold. Signed Van Cleef&Arpels.