Under suitable heating conditions designed for a particular sapphire it is possible to change the color in order to increase its value. It was found that heating African green sapphires in an oxygen atmosphere could improve their quality and thus increase their prices. The color of green sapphires is due to the presence of trace […]
A. Mungchamnankita, T. Kittiauchawalb×, J. Kaewkhaoc, P. Limsuwand aDepartment of Physics, Faculty of Science, Rangsit University, Pathumtani, 12000, Thailand bFaculty of Science and Technology, Thepsatri Rajabhat University, Lopburi, 15000, Thailand cCenter of Excellence in Glass Technology and Materials Science, Faculty of Science and Technology,Nakhon Pathom Rajabhat University, Nakhon Pathom, 73000, Thailand dThailand Center of Excellence in Physics, […]
sapphire, transparent to translucent, natural or synthetic variety of corundum (q.v.; aluminum oxide, Al2O3) that has been highly prized as a gemstone since about 800 BC. Its colour is due mainly to the presence of small amounts of iron and titanium and normally ranges from a very pale blue to deep indigo, with the most […]