All in all there are ten known copper mines and two iron mines on the Ølve peninsula. Geologically, the nine mines on Varaldsøy Island also should be figured in. The industry began at Lilledal in 1642 wth the mining of iron ore. From Jernsmauget by Dyråsen, the iron ore was sent to the iron works in eastern Norway.
Siggjo is a cone-shaped, volcano-like mountaintop in the part of Hordaland where one finds the best preserved volcanic rocks. The rock types originate from one or several volcanoes that spewed out glowing lava and ash. But, the shape of the mountain, as it appears today, formed later and by completely different forces.
In 1868 the first stone workers came to Rubbestadneset to take out the granite for the Skoltegrunns Pier, predecessor of the Skoltegrunns wharf in Bergen. Later granite was also taken out from the area, around Innværs Fjord and UransvågenN. The activity probably peaked around 1900, with over 40 men at work. 15 years later, it was finished.
At Flintaneset by Finnåsvika, in the centre of the municipality, we find the most beautiful and best preserved igneous rocks in western Norway. We must go to Hawaii or Island to find as fine structures as at Bømlo.