Indian And Uk Earrings Jewellery Collection 40

Indian And Uk Earrings Jewellery.
By Farazana aamir.

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. When even the most practised eye may find it difficult to distinguish between stone of difficult species but of very similar colour, simple instruments can sometimes be used to 'analyes' the colour in one way or another and make the separation simple. what we call 'white' light, i.e. light from the sun or other incandescent bodies, is composed of a mixture of all the colours of the rainbow. newton, in the year of the great fire of london (1666), was the first to show
that sunlight has a composite nature. he analysed a narrow beam of light that passed through a chink in the shutter into his darkened room, by the simple expedient of placing a glass prism in the path of the ray. light is variously refracted by a transparent solid according to its wavelenght, the red rays, of longer wavelength, beings less deviated than the shorter, violet, waves.