Catlinite

Native American, Plains (unidentified). Pipe Bowl representing Owl, early 20th century. Catlinite or pipestone, 334 × 538 in. (9.5 × 13.7 cm). Brooklyn Museum
Protohistoric Catlinite pipe, probably late 17th century Ioway, from the Wanampito site in Iowa.

Catlinite, also called pipestone, is a type of argillite (metamorphosed mudstone), usually brownish-red in color, which occurs in a matrix of Sioux Quartzite. Because it is fine-grained and easily worked, it is prized by Native Americans, primarily those of the Plains nations, for use in making ceremonial pipes, known as chanunpas or čhaŋnúŋpas in the Lakota language. Pipestone quarries are located and preserved in Pipestone National Monument outside Pipestone, Minnesota, in Pipestone County, Minnesota, and at the Pipestone River in Ontario, Canada.