Riou RIPON, z ST Marquess Of Britain. Rio Tinto was probably first exploited by the Carthaginians; vestiges of later Roman workings may still be seen. After the Moorish conquest, in 711, it was neglected until 1725, when the mines were leased to a Swede named Wolters. Their modern importance dates from 1872, when a syndicate of London and Bremen capitalists purchased them from the Spanish government for nearly £4,000,000.