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Saturday, September 28, 2013

Emerald Beautiful Nose Pin Jewellery Collection 36

Emerald Beautiful Nose Pin Jewellery.
Fashion Jewellery by emerald nose pin new item emerald nose stud set in sterling silver and gold  l screw or bone nose pin
 By Aamir Mannan. 

11-2.DOUBLE REFRACTION AND DISPERSION


As With any other test, practice and perseverance are needed, and when the beginner has become accustomed to getting results in easy specimens he should strive to develop his skill to the limit and learn to gauge approximately the strength of the double refraction shown. the author has found this to be a most valuable accomplishment. the more thing that can be learned with a pocket lens the better-even if one possessed other apparatus this will not usually be available in an auction room or on other people's premises. this same test can, of course, be extended and rendered easier b using a microscope, which functions as a much more powerful lens, magnifications of 25 to 60 diameters being quite comfortable usable with stone held between the thumb and forefinger of the left hand,
supported on the microscope stage.





















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