Many gemmologists have never learned how to use this method effectively because it is messy and to work with a "dry" microscope is easier and much faster. But recent gem enhancements such as surface diffusion, bulk diffusion, beryllium treatments, etc can only be detected with the stone immersed. Amateurs use water and baby oil in an immersion dish; professionals use a liquid which is close to the refractive index of the stone to be tested. These organic liquids such as methylene iodide (the same liquid used in contact fluid for the refractometer), bromoform, benzyl benzoate and others may be available in your local drug store or from special suppliers. Afterwards the stones have to be cleaned thoroughly in neothene or alcohol because all organic liquids attack plastics and other surfaces.
The update contains the necessary files to display the images of your original CD-ROM disk or floppy diskette in a WWW browser with frames and links to C.I.G.'s website Gemology World.
Please note: The update only works with your purchased Gemstone Inclusion Library; it does not contain any images.
Gemstone Inclusion Library, Version 1.8 Update (Feb. 1, 2002) (update.zip, 34 kB)
Over 120 Black & White line drawings are used in the Gemstone Inclusion Library manual to illustrate typical inclusions in synthetic and natural gemstones.
The enclosed CD contains 100 colour images of inclusions obtained from an immersionscope which can be viewed in a web-browser or printed out.
Eickhorst Immersionscope (horizontal gem microscope)
Gemlab Books and Instruments, a subsidiary of the Canadian Institute of Gemmology is the exclusive distributor of the "Gemstone Inclusion Library"; it contains 25 pages, 5.5"x8.5", with 120 b&W line-drawings, 1 colour plate, CD-ROM disk loaded with over 100 JPEG picture files (also available on floppy disk upon request). A WWW browser such as Netscape or Explorer and VGA monitor with a minimum of 256 colours is required for your computer platform.
Cost is CAN$ 34.95 (includes shipping anywhere in the world)
J. Wolf Kuehn, C.I.G. Director of Education, has compiled numerous inclusion pictures from the comprehensive study collection of the Canadian Institute of Gemmology. It is an ideal reference for serious gemstone identification. The guide contains 120 detailed line-drawings of typical inclusion features found in synthetic and natural gemstones; a diskette with over 100 colour micro-photos of inclusions (in JPEG and .htm format) is included. Most of the pictures were taken with an immersionscope (horizontal micsrosope)allowing the study of internal features with more ease and clarity. If a colour-printer is available high photographic quality can be obtained with special paper.
From the Author's Introduction
After many years of teaching C.I.G.'s Gem Identification courses I felt that other students, practising gemmologists and appraisers might equally benefit from the various instructional materials used in the "Accredited Gemmologist" diploma program such as the Gemstone Inclusion Library.
When attending conferences, workshops and gem shows it was one of my most important tasks to look for new gem materials - natural, synthetic, invented, enhanced and/or assembled. Today I can state with great confidence that almost any possible gemstone encountered in the market-place is represented in the study collection of the Canadian Institute of Gemmology (C.I.G.); that includes natural gems such as Taaffeite and Benitoite as well as synthetic gems such as Knischka and Lechleitner rubies and emeralds.
During an evaluation of a gem or a piece of jewellery the most important part is the proper identification of the gem materials. In most cases this is a straightforward procedure; however, if the gem happens to be a ruby, sapphire, emerald, alexandrite or opal, it may require the microscope to study the internal features before deciding whether it is a natural or man-made product.
This is particularly true in the case of the latest flux-fusion and hydrothermal synthetic gems which include the Kashan, Knischka and Ramaura rubies, the Chatham, the Lennix, Biron and Regency emeralds and others. Most of us do not have access to more sophisticated testing equipment such as the electron microprobe or a Raman spectroscope. Our work must depend on the recognition of visual clues including diagnostic inclusions, colour zoning and growth patterns.
I have attempted to show many of these features in the following black and white drawings and the numerous colour microphotos which can be viewed on the accompanying diskette. For the latest up-to-date information please visit C.I.G.'s website GEMMOLOGY WORLD at http://www.cigem.ca or write to the Canadian Institute of Gemmology, P.O. Box 57010, Vancouver, B.C., V5K 5G6 CANADA.
I wish to thank the Gemstone Training Centre Ruppenthal in Idar-Oberstein, Germany for their support in this project.
J.Wolf Kuehn, Director of Education, C.I.G.
Vancouver, B.C., August 1996 <
(the images are posted for educational purposes only)
For View/Download (files are 175k each)
Animation 1: Air-bubbles moving around in crystal
Animation 2: Beautiful inclusion picture of topaz The bubbles are probably fluid carbon dioxide; see Inclusion Glossary below.
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