Dolomite is a rock-forming mineral forming sparry masses in the marble at the Grandview Quarry, NW NW NW Sec. Drusy crystals of rhombehedral dolomite are common in the dolostones of the Prairie du Chien group throughout the county. These are grey to buff to rarely a very pale pink. Some quarries where these creystals are found are in the NW NW Sec. SE SE Sec.
Dolomite is an important rock-forming mineral in the dolostones throughout the county.
It may be found, among many other places, at a quarry near Nasbro in the center of Sec. Dolomite is abundant throughout the Upper Mississippi Valley zinc-lead district in the county both as a component of the host rock dolostones and as a later hydrothermal gangue mineral. Later veins contain pink to grey crusts of dolomite crystals in association with galena, sphalerite, marcasite, pyrite and calcite. Most localities listed for the county under these minerals contain dolomite as well. Dolomite is abundant throughout the Upper Mississippi Valley zinc-lead district in the county both as a component of the host rock dolostones and as a later hydrothermal gangue mineral.