Democratic Sentinel, Volume 19, Number 26, Rensselaer, Jasper County, 5 July 1895 — Test for Real Diamonds. [ARTICLE]

Test for Real Diamonds.

A real diamond is not acted on by acids or alkalies. When rubbed on a piece of silk it acquires positive electricity, and will attract small pieces of wool, cotton and paper, and this electrification will last sometimes half an hour. A real diamond, if exposed to the sun's rays for a time, possesses a distinct phosphorescence in the dark. It gives only a simple refraction—that is, it gives only a single image of a bright light when that is viewed through its facets. This last test is a very goo’d one, and the electrification and phosphorescent qualities afford two other good tests. Jewelers usually test with a file. If that affords no proof, the joweler places the stone into a leaden or platinum cup with some powdered flour spar and a little oil of vitriol. The vessel is then placed over a charcoal fire in some place where the strong draught will carry off the noxious.vapors evolved. When these latter have ceased rising the mixture in the vessel is allowed to cool, and the stone is then fished out with a glass rod. If it is genuine, no change will be noticeable; if false, it will be corroded by the acid.