Barium borate Barium borate Barium borate is an inorganic compound, a borate of barium with a chemical formula BaBO or Ba(BO). It is available as a hydrate or dehydrated form, as white powder or colorless crystals. The crystals exist in the high-temperature α phase and low-temperature β phase, abbreviated as BBO; both phases are birefringent, and BBO is a common nonlinear optical material. Barium borate exists in two major crystalline forms: alpha and beta. The low-temperature beta phase converts into the alpha phase upon heating to 925 °C. β-Barium borate (BBO) differs from the α form by the positions of the barium
Argentium sterling silver Argentium sterling silver Argentium silver 935 is a modern sterling silver alloy, containing 93.5% silver. The traditional sterling alloy (92.5% silver + 7.5% copper) is modified by removing some of the copper and adding the metalloid germanium. Argentium silver 960 is a higher-purity jewellery alloy also containing germanium. It meets the standard for Britannia silver (95.84% silver) hallmarking. Argentium silver is the result of research by Peter Johns at the Art and Design Research Institute (ADRI), School of Art & Design, Middlesex University. The project began in 1990 with research on the effects of germanium additions to silver alloys. Germanium