E-Line Gemological Refractometer User Guide
E-Line Gemological Refractometer User Guide (Eng) B+S Code : 44-895 Issue 3A November 2008 Order Code 44-861 Description E-Line Gemological Refractometer © Copyright Bellingham + Stanley Ltd 2008 Every effort has been made to ensure the accuracy of the contents of this manual. However, Bellingham + Stanley Ltd can assume no responsibility for errors contained in the manual or their consequences. Printed in United Kingdom. Bellingham+Stanley Ltd.
Product Description Refractive Index is one of the most important optical parameters used to identify and authenticate polished precious and semi-precious gemstones. The E-Line Gemological refractometer is a low cost, lightweight measuring instrument used by jewellers and traders of gemstones. The Gemological refractometer can also be used to identify whether a particular stone is Isotropic or Anistropic (uniaxial or biaxial).
Operating Instructions Method of Operation (Singly Refractive) 1. Place the instrument on a suitable table. Open the upper cover. Drop a few drops of contact liquid (see table over page) onto the surface of the prism using a thin glass bar or soft wooden stick. (CAUTION: Contact Liquid - Read Material Safety Data Sheet). 2. Gently place the polished surface of gemstone on the prism, depressing it lightly to make sure contact liquid is distributed evenly between the gemstone and measuring prism. 3.
Contact Liquids Contact liquids are required to expel air between the measuring prism and gemstone under test. The contact liquid must be of a higher refractive index value than the gemstone under test; otherwise the refractive index of the contact liquid will be read.
Typical Refractive Index values Gemstones Agate Alexandrite Almandine Amber Amethyst Ammolite Andalusite Apatite Aquamarine Axenite Beryl Beryl, Red Chalcedony Chrome Tourmaline Citrine Clinohumite Coral Crystal Crysoberyl, Catseye Danburite Diamond Emerald Emerald Catseye Flourite Garnet, Grossular Garnet, Andradite Garnet, Demantiod Garnet, Mandarin Garnet, Pyrope Garnet, Rhodolite Garnet, Tsavorite Garnet, Uvarovite Hauyn Iolite Jade, Jadeite 1.544 - 1.553 1.746 - 1.755 1.750 - 1.830 1.539 - 1.545 1.
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