Are They Real?

Radio Record, Volume III, Issue 33, 28 February 1930, Page 33

Are They Real?

Tests for Gems WHEN an artificial jewel is examined under a powerful magnifying glass, it will generally be found to contain a number of minute vesicles, produced by the bubbles of air entangled in the liquid glass while the gem was being made. This is at once a proof of the nature of the jewel in which they are found, nothing of the kind being present in the real gem. Another method of distinguishing artificial: from real gems, is that the glass of which they are formed is considerably softer than a true jewel, and readily udmits of being scratched by an onyx, or fine quartz sand. Artificial gems can. also be distinguished by their power of conducting heat being much inferior to that of a real gem. For, when a false jewel is breathed on, the moisture condensed from the breath will remain: much longer than would happen in the case of a real jewel. So, also, when an imitation gem is placed in contact with the warm skin, it will cease to produce a feeling of coldness sooner than a real jewel. Real gems may sometimes be found to be phosphorescent; that:is to say, when they are long exposed to the sunshine, they will afterwards give out a certain amount of light if placed in a dark room. This is especially the case with the diamond. Now, as the property of being phosphorescent in the dark is not possessed by paste. it proves that the jewel that does shine in the dark is a real one. The nature of jewels may also he learnt by rubbing them on a piece of warm silk, so as to render them -sufficiently electrified to attract smal] feathers and similar objects. In the case of false gems, they will be found to retain the electricity for only from half-an-hour to an hour; while the true jewels continue to exert the power of attraction they have thus acquired from a quarter of a day to a day and a half.