Optimism was large when an English company found pyrite ore, first in Valaheia and later in occurrences that got named "Nygruva" (New Mines). The mines at Valaheia had an annual production of up to 16 000 tonnes of pyrite in the beginning. Falling prices eventually led to reduced activity, until it ceased operations at the end of the 1800s. Since then, the mine has been in operation periodically, with most activity during the First World War, when 6000 tonnes of ore were taken out.
The deposit at Valaheia stretches deep underground from the area of the mine toward the northwest. The ore contains 40% sulphur and 0.4% copper. The ore from Nygruva has a higher zinc and copper content, but otherwise they are quite similar.
The new road to the north on Varaldsøy Island makes it easy to get to these mining areas. From the south one first passes Nygruva. Here, there are remains from the transport system and the mine corridors through which the ore had been removed. Further to the north you take off to the right up the old road to the Valaheia mines. The ore is found in big slag piles between the old homesteads and the roads. The mining roads are located a bit higher up in the valley. Here, one can look down over hundred year-old mine shafts that are around 90 metres deep.
