gems, gemology, gem identification, gem property tables

It often happens that a dealer in gems, who has gained his experience by constantly handling large quantities of precious stones in the rough and cut states, is able to settle in a few moments some important question of dispute which it would take a clever mineralogist as many hours to decide, and it is surprising to what a degree of keenness the senses can be educated by the continual concentration of the faculties upon minute details, enabling one not only to discriminate between gems of different kinds, but to pick out, say, from a parcel of cut diamonds weighing several thousands of carats, a single stone which owes its origin to a different mine from the remainder of the parcel. It is, however, impossible to overestimate the value of the methods of testing precious stones which have been placed at our disposal by the science of mineralogy, by the application of which the keen judgment of the expert should be endorsed and made doubly sure.