The only metal quarried in British Columbia prior to explorers and settlers arriving to the province was copper. Silver was introduced during the mid-1800s in the form of coins, which would be hammered out, rolled, and then shaped for engraving. Sterling silver is now the standard metal used for hand-engraving by Northwest Coast First Nations artists. It is popular because it is durable yet soft enough to engrave by hand. It also oxidizes nicely, unlike gold, which allows the designs to stand out.