Barium carbonate as a flux, a matting and crystallizing agent and combines with certain colouring oxides to produce unique colours not easily attainable by other means. Its use is somewhat controversial since some claim that it can leach from glazes into food and drink. To provide a safe means of use, BaO is often used in fritted form. In the brick, tile, earthenware and pottery industries barium carbonate is added to clays to precipitate soluble salts (calcium sulfate and magnesium sulfate) that cause efflorescence. Barium carbonate Barium carbonate (BaCO), also known as witherite, is a chemical compound used in rat poison, bricks,
Sterling silver products. Colonial silversmiths used many of the techniques developed by those in Europe. Casting was frequently the first step in manufacturing silver pieces, as silver workers would melt down sterling silver into easily manageable ingots. Occasionally, they would create small components (e.g. teapot legs) by casting silver into iron or graphite molds, but it was rare for an entire piece to be fabricated via casting. Next, silversmiths would forge the ingots into the shapes they desired, often hammering the thinned silver against specially shaped dies to "mass produce" simple shapes like the oval end of a spoon. This process occurred