Analysis of Gemstone Colour Losing in Stone-in-Place Casting

Stone-in-place casting is a very complicated process, and there are many factors to affect on the quality of the products, especially the gemstones have to withstand the roasting at high temperature and heat impact caused by metal liquid during pouring. Any factor will probably cause the problem such as cracking or appearance changing of gemstones. In this paper, the gemstone colour losing that usually occurs in stone-in-place casting process is described, the causes of colour losing are analyzed and corresponding resolutions are suggested.