Jasper County Democrat, Volume 1, Number 17, Rensselaer, Jasper County, 6 August 1898 — How Gems Lose Their Luster. [ARTICLE]

How Gems Lose Their Luster.

Among the maladies common to all gems of color is one which arises from exposure to the light for a period. They lose color. The colors of the emerald, sapphire and ruby are as nearly permanent as possible, but experiments made a few years ago in Berlin and Paris showed these stones suffered by exposure to the light and a ruby shown two years In a shop window was many shades lighter than Its mates, which had been kept In darkness.