Catlinite is not an approved mineral species but an argillite, that is a mudstone with variable amounts of silt-sized particles composed predominantly of indurated clay
Origin of name: after American lawyer, painter and author George Catlin, who visited the Minnesota quarries in 1835
Synonyms and trade names: pipestone
Can be confused with: above all with red jasper
Localities: USA, mostly at pipestone quarry, Pipestone County, Minnesota. Other localities are Delta, Utah, where catlinite is a by-product of slate mining, as well as Arizona, Iowa, Ohio, South Dakota and Wisconsin.
Handling: catlinite is rather soft and can be cut and carved easily and with simple tools. Also it is highly heat-resistant. Due to these two properties it has been used by native Americans for the production of ornaments, charms and amulets and, above all, ceremonial pipes for centuries.
potos: left: Indianertosset, CC BY-SA 4.0 , via Wikimedia Commons, right: User:Billwhittaker, CC BY-SA 3.0 , via Wikimedia Commons
Worth knowing: Catlinite owes its characteristic red colour to hematite. Sometimes it shows white inclusions called "stars"