Sterling silver is an alloy of silver made up of around 93% silver and 7% other metals, such as copper, all blended together to form the substance. what type of mixture is sterling silver? a heterogeneous mixture, because the different components are mixed evenly within the substance a heterogeneous mixture, because the different components are mixed unevenly within the substance a homogeneous mixture, because the different components are mixed evenly within the substance a homogeneous mixture, because the different components are mixed unevenly within the substance