Maxixe

Maxixe (pronounced mah-sheesh or mah-she-she) is also known as Dark Blue Beryl It is found only in Brazil and is extremely rare. It gets its deep blue color from natural radiation within the earth. Its color is somewhat unstable and may fade with exposure to heat, ultra-violet light, or sunlight. Occasionally aquamarines are irradiated to produce a gem with Maxixe-like color, but it too is unstable and fades quickly.

The original document is available at http://www.embassyemeralds.com/tiki-index.php?page=Maxixe