Crystal system Orthorhombic.
Appearance Single crystals are rare. Chrysoberyl is usually found as V-shaped twins or sometimes repeated twinning of flattened crystals, giving an appearance of hexagonal symmetry. lt is normally cloudy, but when transparent, has considerable luster. The most common color is yellow, but it can also be grayish, greenish yellow, or even more or less green.
Physical properties It is quite hard: 8.5 on Mohs' scale, with a density of around 3.7 g/cma. The refractive indices are roughly Fla 1.74, and ny 1.75. It has weak prismatic cleavage.
Genesis Chrysoberyl occurs in granite-pegmatites and is an uncommon mineral.
Occurrence lt is found in some pegmatites in the United States, in the Ural mountains in the Soviet Union, and in Sri Lanka, Rhodesia, Brazil, Madagascar, and Italy.