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,
Tibetan silver iron 'cheese metal' casting, overlaid with this pewter and silver plating. Dependent on source, these can be either thick and robust, or attractive but easily broken due to a loose, fragile inner casting. The latter productions are therefore only suitable for small castings up to around 12 mm, or transient 'fashion' jewelry with a short lifespan. Tibetan silver Tibetan silver is used primarily in jewelry components, and is similar to pewter – an alloy of copper, and sometimes tin or nickel, with a small percentage of pure silver. Its overall appearance is of aged silver, but it can be polished