Amateur geologists have long shown an interest in the blasting work in this part of the Fjell municipality. Here, fresh openings along fractures and faults in the bedrock have been shown several places to contain open spaces or cracks that are partially filled with crystals. These occurrenceswere discovered in connection with blasting work along the new road from Bergen toward Øygarden, and through the development of the industrial area at Ågotnes.
The minerals grow when the warm gasses and fluids circulated in the fractures and faults more than 160 million years ago, long before the bedrock had become exposed at the surface. The overheated water can dissolve the mineral material from one place in the earth's crust, and deposit it out slowly as beautiful crystals another place. This can occur a ways down under the earth's crust, where the water is hot enough that it can effectively dissolve and transport the mineral, but not too deep for the open space to exist.
There have been finds of exquisite crystals, among them white feldspar, clear quartz, purple amethyst, green epidote, chlorite and golden pyrite. Especially typical for the region, nonetheless, is fluorite crystals, with their deep purple and occasionally greenish colours. The finest examples have been collected by mineral collectors long ago, but new episodes of blasting will be able to expose new finds. Remember to ask the landowner if you wish to take loose samples. The museum in Bergen has exhibited a number of fine specimens from the Ågotnes area.