Show How Diamonds Are Tested The geological survey says that the ordinary tests to determine the genuIneneSs genuineness of a diamond are to test Its specific gravity hardness and refractive refractive tive tivo Index When further proof Is d de desired de- de sired aired the stone is burned In an atmosphere atmosphere atmosphere atmos atmos- phere of ot hydrogen An ordinary fire will not affect a n diamond If only the atmosphere of the time air Is present Diamonds Din Dia monds are the hardest substance known |