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.
See Emerald offers. Colombian emeralds will typically be the most expensive followed by Brazilian and Zambian stones. The reasoning is related to the color. Colombian emeralds get their color primarily from the trace amounts of the element chromium which is responsible for some of the purest greens in gemstones. Brazilian emeralds get their color primarily from trace amounts of the element vanadium and Zambian emeralds get their color from iron.