Gemstone usually found in. For example, diamonds, which have a cubic crystal system, are often found as octahedrons. Gemstones are classified into different "groups", "species", and "varieties". For example, ruby is the red variety of the species corundum, while any other color of corundum is considered sapphire. Other examples are the emerald (green), aquamarine (blue), red beryl (red), goshenite (colorless), heliodor (yellow) and morganite (pink), which are all varieties of the mineral species beryl. Gems are characterized in terms of refractive index, dispersion, specific gravity, hardness, cleavage, fracture and luster. They may exhibit pleochroism or double refraction. They may have luminescence
GemStone IV named "Avalon" is available for Mac OS X. No official Linux client exists. "GemStone" was first demonstrated to GEnie in 1987 before Simutronics was officially incorporated. It was only used as a demonstration model and was never available to the general subscribers. "GemStone ][" was released in April 1988 to GEnie customers. However, "GemStone ][" was very short-lived, and "GemStone III" went into open beta testing in December 1989, officially launching on February 1, 1990. The transition from "][" to "III" maintained significant portions of the environment, but not all, and character records were not maintained over the transition, requiring