Show phosphorescent diamonds an expert in gems has lately called caled at attention to a property in the diamond which has not hitherto been fully appreciated precia ted robert boyle ment mention ionn a diamond that became phosphorescent simply by the heat of the hand absorbed light on being held desir near acan a can ean dle and emitted light on being briskly rubbed observations by markum kunz the gem expert confirm boyles statement that diamonds become phosphorescent I 1 in the dark after exposure to sunlight or electric light by being rubbed on wood cloth or metal this pro property pETty is an important one its as it will willhelm help atis tb non expert to distin distinguish aguish between tha true diamond and other hard stones as well as imitations none of which ich Is said to ech exhibit alt this phenomenon |