Barium permanganate heptoxide. Barium permanganate Barium permanganate is a chemical compound, with the formula Ba(MnO). Barium permanganate may be produced by disproportionation of barium manganate in a mildly acidic solution, or by oxidation of barium manganate with strong oxidants. Preparations relying on aqueous reactions of barium manganate are extremely slow process due to the low solubility of the manganate. Permanganic acid can be prepared by the reaction of dilute sulfuric acid with a solution barium permanganate, the insoluble barium sulfate byproduct being removed by filtering: The sulfuric acid used must be dilute; reactions of permanganates with concentrated sulfuric acid yield the anhydride,
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