A pound coin originally weighed one troy pound of sterling silver, giving the currency the name "pound sterling". "Sterling silver" means mixed metal that has 92.5% or more real silver. One pound sterling was originally divided by 240 sterling pence. This was because there are 240 pennyweights in a troy pound. So a single one–pound coin weighed one troy pound and a single 1–penny coin weighed one pennyweight.