 Silver is also produced during the electrolytic refining of copper and by application of the Parkes process on lead metal obtained from lead ores that contain small amounts of silver.Commercial grade fine silver is at least 99.9 percent pure silver and purities greater than 99.999 percent are available.The principal sources of silver are copper, copper-nickel, gold, lead, and lead-zinc ores obtained from Canada, Mexico, Poland, Peru, Bolivia, Australia and the United States.