The red variety of this gem has only been found in one place on Earth: the Wah Wah Mountains of Utah. A 217.8 carat one of these inscribed with Islamic prayers called "the Mogul" or "Mogul Mughal" auctioned for over US$2 million in 2001. In fiction, the walls of a famous city were of the color of this gem. Identify this gemstone which sees a vast majority of its gems come from Columbia or Brazil.
Emerald