English: Antimony oxychloride powder. Pewter was dissolved in hydrochloric acid, leaving antimony and copper behind. A small chunk of pewter accidentally got into the antimony. The antimony was dissolved in a hydrochloric acid-hydrogen peroxide solution. This made antimony trichloride, copper(II) chloride, and some tin(II) chloride from the piece of pewter. It was reacted with sodium carbonate. As soon as a precipitate was seen, the sodium carbonate addition was stopped. The pH was rather acidic. The solution was filtered and the precipitate, which turned from a white-tan to a pale tan, was allowed to dry on filter paper. The dried precipitate was scraped onto a black lid where it was photographed.