I am currently the Digital Coach for the City of London and the West, within the London and Midlands Region. My role in a nutshell is to coach our leaders on sustainable banking whilst making the lives our of customers easier.
(There is also genuine color-change sapphire which mimics alexandrite, as well as color-change garnet that can be a real fooler.). The first thing to do is check the refractive index of the stone, since each material has unique optical properties.
Sapphire occurs in many colors ranging from colorless to black. When a corundum variety is termed sapphire it indicates the blue variety. Any other color (except red, which is named ruby) will have a prefix before sapphire, such as yellow sapphire. Causes of color: 1  sapphire (blue) - charge transfer between Ti and Fe.