Offerdal is a Quartzite of feldspar metasandstone with a fine structure. The main minerals of the schist are quartz, feldspar and mica. Offerdal is a hard and solid building stone with a gray wavy surface. The stone I best suited for facades, flooring and staircases.
Oppdal Quartzite looks like the Offerdal schist. The main minerals of the schist are Quartz, feldspar, mica and epidote. The mineral content fluctuates and decides if the schist is light or dark, plain or speckled. Oppdal has more grey tones and a fluctuating surface structure. The schist is hardwearing, timeless and maintenance-free and is suited for both indoor and outdoor use.
The Otta schist is a phyllite schist, with fine-grained light mica. The main minerals are chlorite, quartz and feldspar as well as hornblende and garnet crystals. Sulphides and pyrites grants the stone a rusty look on the upper burst of the stone. The Otta schist is unique among all types of schist in the world. Characteristic for the Otta schist is the rosettes of black amphibole crystals and small crystals of garnet. The Otta schist is suited for rooftops, facades as well as an interior stone for floors and walls in all types of rooms. The black Otta schist will turn golden and gradually rust if used outside. A roof can change from black to a rusty look in a year, in other cases it can take decades, and some roofs never gets the rusty look.