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 University, Belfast, led by Professor Trevor Whittaker. The Queen's University, Belfast studies were co-funded by the Engineering and Physical Sciences Research Council and Allan Thomson, who had previously founded and led the UK’s first commercial wave energy company, Wavegen. In 2005, Allan Thomson founded Aquamarine Power to progress the commercialisation of the Oyster device. In 2007 Scottish & Southern Energy subsidiary Renewable Technology Ventures Limited invested in Aquamarine with a further investment in 2010. In February 2009, Aquamarine Power and Queen's University, Belfast signed an agreement to extend their R&D partnership to 2014. In February 2009, Aquamarine Power signed an