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
Aquamarine Power Aquamarine Power Aquamarine Power was a wave energy company, which was founded in 2005 to commercialise a wave energy device concept known as the Oyster wave energy converter. The company's head offices were based in Edinburgh. The company had further operations in Orkney, Ireland, Northern Ireland and the United States. Its chief executive officer was Martin McAdam, who joined the company in 2008. The company was advised by Trevor Whittaker, inventor of the Oyster concept, and Stephen Salter, inventor of the Salter's Duck. The Oyster concept originated from studies conducted in 2003 by the wave power research team at Queen's