Indian Assam Bridal Wedding Jewellery Collection 24

Indian Assam Bridal Wedding Jewellery.
By Aamir Mannan.
4.REFRACTIVE INDEX AND ITS MEASUREMENT

It has already been stated that each mineral has a definite refractive index by which it can be identified on the refractometer; list of these indices will be found on p. 27, and at the of the post. for the benefit of those who like to have at least a rough idea of the working of an instrument which they are using, a short description of the basic principle upon which all gem-tasting refractometer depend followers. however, those, who would like to know how to use a refractometer, but who prefer to shirk such explanation, can skip the next section and await the strictly practical directions which will be given later, on

p.21. what followers can best be understood by considering the diagram, figure 2.2. here rays of light are considered passing from a dense medium into a rarer one, say from glass into air. the rays will then be refracted away from the normal, NOM (the revers process of the former case considered in figure 2.1).