What are lattice diffusion sapphires?
The mechanism by which atoms or ions move through solids is known as diffusion. Lattice diffusion is a treatment process that uses heat and chemicals to diffuse an element from an external source into a gemstone to artificially change its color. Even the most perfect crystal has places in its lattice where atoms are missing. These holes are termed “vacancies.” In the case of corundum, which is made up of aluminum and oxygen atoms, the higher the temperature, the more missing atoms there will be. The color change depends on the type of element that is diffused into the corundum, its inherent chemical composition and the conditions under which the diffusion takes place. Early in 2002, a large number of pinkish orange sapphires came into the jewelry market. It became apparent that corundum treated by a new technique had been introduced into the marketplace unannounced, particularly in Japan. Careful research demonstrated that this new process involved diffusion of the element beryllium (B
