Mineral site, and from there further subdivided by the chemistry of the W site. The Y and Z sites can accommodate a variety of cations, especially various transition metals; this variability in structural transition metal content gives the tourmaline group greater variability in colour. Other cyclosilicates include beryl, AlBeSiO, whose varieties include the gemstones emerald (green) and aquamarine (bluish). Cordierite is structurally similar to beryl, and is a common metamorphic mineral. Sorosilicates, also termed disilicates, have tetrahedron-tetrahedron bonding at one oxygen, which results in a 2:7 ratio of silicon to oxygen. The resultant common structural element is the [SiO] group. The
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