Alum shale is a black clay shale, created in an oxygen deficient sea where remains of dead plants and animals were deposited on the seafloor. The organic material has not decomposed but has been stored in the shale, and due to high pressure and heat, it has been transformed into oil. Thus, alum shale can be used as fuel for the lime kilns. The most useful lime to burn in the kilns is anthraconite or stinkstone. It is a type of limestone that is embedded as “lenses” in the alum shale. The contact surface between shale and stinkstone is clearly visible. Stinkstone can be found in various forms, e.g. containing prismatic calcite crystals. The stinkstone contains a relatively high amount of organic materials, making it smell of petroleum or kerosene when you strike it. That is where the name “stinkstone” comes from. The conditions for lime burning have been perfect here: both the limestone and the fuel could be quarried at the same location.
Silverfallet is one of the most popular destinations in Skövde and well worth a visit all year round – especially in winter when it becomes a fairy tale ice landscape!