Where did all the GOLD (and silver) come from?

The article focuses on the gold and silver coins. It states that the coins have been a vital part in the life of British Isles, however the amount of these coins that have been mined in the islands has always been small. It notes that the other source of gold used by Celts came from western central Wales. It also mentions that silver is elaborately combined with lead in the British Isles.