A mineral lode including Lead ore (Galena) and Copper ore (Chalcopyrite) runs within half a mile of St Merryn church, and from 1823 this was mined by Wheal Friendship mine, initially for silver. There was a further open cut on the same lode known as Trevorgus Mine sited south west of St Merryn, and in 1834 these amalgamated as Trevorgus and Treveglos Mines. The combined mine was abandoned in 1839, but in 1838 it produced only 24 tons of Lead Ore.