Minerals described in 1890

Nesquehonite is a mineral of magnesium carbonate (). It represents the trihydrate of magnesium carbonate, and has the total formula . It was described in 1890 by F. A. Genth and S. L. Penfield and is named after its type locality of Nesquehoning, Pennsylvania, where it was sampled from a coal mine. Nesquehonite can form from the related pentahydrate Lansfordite by dehydration at room temperature.