Bicolored (aquamarine-morganite) beryl from a 1986 discovery at the Bananal mine is described. Most of the cutting material was of carving grade, but a small percentage of the crystals contained faceting-quality morganite gem nodules. This is the first published report of gem nodules of a species outside the tourmaline group. Much of the Bananal morganite is of a pleasing orange to pink-orange color that changes to pink on extended exposure to heat or sunlight. The inclusions in the nodules appear to be limited to muscovite crystals, while the rest of the material (both aquamarine and morganite) contains two- and three-phase inclusions, but little or no muscovite. The cause of the gem nodules is not established, but it may relate to the presence of the same type of variation in mosaic texture observed in some color-zoned tourmaline crystals.
