Catlinite is a type of argillite

Argillite

An argillite is a fine-grained sedimentary rock composed predominantly of indurated clay particles. Argillaceous rocks are basically lithified muds and oozes. They contain variable amounts of silt-sized particles. The argillites grade into shale when the fissile layering typical of shale is...

 (metamorphosed

Metamorphic rock

Metamorphic rock is the transformation of an existing rock type, the protolith, in a process called metamorphism, which means "change in form". The protolith is subjected to heat and pressure causing profound physical and/or chemical change...

 mudstone

Mudstone

Mudstone is a fine grained sedimentary rock whose original constituents were clays or muds. Grain size is up to 0.0625 mm with individual grains too small to be distinguished without a microscope. With increased pressure over time the platey clay minerals may become aligned, with the...

), usually brownish-red in color, which occurs in a matrix

Matrix (geology)

The matrix or groundmass of rock is the finer grained mass of material in which larger grains, crystals or clasts are embedded.The matrix of an igneous rock consists of finer grained, often microscopic, crystals in which larger crystals are embedded. This porphyritic texture is indicative of...

 of Sioux quartzite

Sioux Quartzite

The Sioux Quartzite is a Proterozoic quartzite that is found in region around the intersection of Minnesota, South Dakota, and Iowa, and correlates with other rock units throughout the upper midwestern and southwestern United States...

. Because it is fine-grained and easily worked, it is prized by Native Americans

Native Americans in the United States

Native Americans in the United States are the indigenous peoples in North America within the boundaries of the present-day continental United States, parts of Alaska, and the island state of Hawaii. They are composed of numerous, distinct tribes, states, and ethnic groups, many of which survive as...

 for use in making sacred pipes such as calumet

Calumet (pipe)

A Calumet is a ceremonial smoking pipe used by some Native American Nations. Traditionally it has been smoked to seal a covenant or treaty, or to offer prayers in a religious ceremony.- Etymology :...

s (Fr: "hollow reed") and chanunpa

Chanunpa

Chanunpa, or Chanupa, is the Sioux language name for the sacred, ceremonial pipe and the ceremony in which it is used.The Chanunpa is one means of conveying prayers to the Creator and the other sacred beings...

s. Pipestone quarries are located and preserved in Pipestone National Monument

Pipestone National Monument

Pipestone National Monument is located in southwestern Minnesota, just north of the city of Pipestone, Minnesota. It is located along the highways of U.S. Route 75, Minnesota State Highway 23 and Minnesota State Highway 30....

 outside of Pipestone, Minnesota

Pipestone, Minnesota

As of the census of 2000, there were 4,280 people, 1,900 households, and 1,138 families residing in the city. The population density was 1,090.8 people per square mile . There were 2,097 housing units at an average density of 534.4 per square mile...

, in Pipestone County, Minnesota

Pipestone County, Minnesota

As of the census of 2000, there were 9,895 people, 4,069 households, and 2,726 families residing in the county. The population density was 21 people per square mile . There were 4,434 housing units at an average density of 10 per square mile...

, and at the Pipestone River in Ontario

Ontario

Ontario is a province of Canada, located in east-central Canada. It is Canada's most populous province and second largest in total area. It is home to the nation's most populous city, Toronto, and the nation's capital, Ottawa....

, Canada

Canada

Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...

.

The Canadian quarry is no longer used, although there are quarries in Canada where prized black stone is gleaned. The Ojibwa

Ojibwa

The Ojibwe or Chippewa are among the largest groups of Native Americans–First Nations north of Mexico. They are divided between Canada and the United States. In Canada, they are the third-largest population among First Nations, surpassed only by Cree and Inuit...

 use the black stone for their sacred pipes. The red catlinite from the Pipestone quarries is the second softest rock in the world, and it lies under Sioux quartzite, the second hardest rock in the world. Only hand tools are used to reach the catlinite so it takes a long time to get to it. Only enrolled Native Americans are allowed to quarry for the stone at the Pipestone National Monument, and thus it is protected from over-mining.

Utah Pipestone has a more variable range of hard and soft forms, since it occurs as layers between deposits of harder slates. Utah Pipestone is a by-product of slate mining in Delta, Utah and several natural deposits in the area have been mined and used for pipemaking by Native Americans in the area for millennia. Minnesota Catlinite is buttery smooth, but contains quartzite like all forms of catlinite (which is what cements the rock particles together) and can be cut with a regular hacksaw or even a knife, it comes out of the ground a pinkish color often with a cream layer protecting it from the hard quartzite. It is weaker and more subject to breaking under stress than Utah pipestone
The term Catlinite came into use after the American painter George Catlin

George Catlin

George Catlin was an American painter, author and traveler who specialized in portraits of Native Americans in the Old West.-Early years:...

 visited the quarries in Minnesota in 1835; but it was Philander Prescott

Philander Prescott

Philander Prescott . He was a native of Phelps, Ontario County, New York...

 who first wrote about the rock in 1832, noting that evidence indicated that American Indians had been using the quarries since at least as far back as 1637.

A large range of pipestones exist, not just those in Minnesota, and numerous native American tribes used a variety of materials and catlinites for pipemaking. Most Catlinite deposits exist beneath the level of groundwater or are in deep enough layers where the soil is constantly moist as the iron compounds which give catlinite its red color quickly convert into iron oxides when exposed to the elements and the stone degrades and breaks down.

In the UK, pipeclay, or pipe clay, has meant a pale, whitish clay

Clay

Clay is a general term including many combinations of one or more clay minerals with traces of metal oxides and organic matter. Geologic clay deposits are mostly composed of phyllosilicate minerals containing variable amounts of water trapped in the mineral structure.- Formation :Clay minerals...

 since the 18th. century. The OED defines it as "fine white clay which forms a ductile paste with water". It was traditionally used for all sorts of polishing and whitening purposes as well as for making tobacco pipes and pottery.

External links

• Mississippi Valley Archaeology Center at the University of Wisconsin - La Crosse: Describes the process of making pipes from Catlinite