Brass – that lovely, shiny gold metal alloy – is a combination of 60 to 70% copper and 30 to 40% zinc. It is revered for its strength, rust-resistance and acoustical qualities. Copper ions in brass can kill bacteria and viruses on contact. From trumpets and trombones to faucets, pipes, locks, gears and kickboards, brass is a frequent go-to material for function and beauty.