infocus #7 September 2007 Photomicroscopy for gemologists

Just because you don't see it, doesn't mean it isn't there

DOI: 10.22443/rms.inf.1.24

Many areas in the jewellery industry - education, gemological research, lecturing, publication, and laboratory and inventory documentation, to name a few - either require or benefit from high quality photomicrography. This article reviews the basic requirements of gemological photomicrography and introduces new techniques, advances, and discoveries in the field. Proper illumination is critical to obtaining the best possible photomicrographs of gemological subjects, as is the cleanliness of the photomicroscope and the area around it. Equally as important is an understanding of the features one sees and the role they might play in the identification process.

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Author

John I. Koivula

John Koivula is chief research gemologist at the GIA Gem Trade Laboratory in Carlsbad, California. John has been studying and photographing the microworld of gemstones since 1961. As an extension of his inclusion research and microscopy he has developed several useful illumination techniques applicable to gemology. He introduced fi ber optic illumination to gemology and discovered many of the micro-characteristics now routinely used in the separation of treated stones from natural gems, such as internal diffusion in proving treatment, chromophore cannibalization, and the usefulness of intact carbon dioxide and other fl uid inclusions in proving natural color. Koivula has authored or co-authored more than 800 articles and notes on gemstone inclusions, microscopy and related topics for a wide variety of professional and trade publications. His photomicrographs have graced the covers and contents of numerous books and journals. He has also won several international photographic awards including “Nikon’s Small World Competition” and Kodak’s “Professional Photographer’s Showcase.