Pipestone is about as hard as your fingernail.
If the weather is nice, go out and walk the Circle Trail. Visit the Exhibit Quarry—#16 on the Circle Trail. Walk to the bottom of the quarry and stop at the rock wall.
Geology is the study of rocks and minerals. Here at Pipestone National Monument we have three types of rock:
Pipestone The type of pipestone found here is called Catlinite. Sioux Quartzite This is the hard pink-colored rock that makes up the cliffs at the Monument and the historic buildings in Pipestone City. This is also the rock that the quarriers need to dig through to get to the pipestone layer. Granite These hard rocks are not from this area but were brought here by glaciers. Good examples of granite are the Three Maidens.
Estimate how tall you think the quartzite layer is.
Pipestone: this layer is approximately 1 foot high⇒ Quartzite: this layer is approximately
Quarrying
Quarrying is a difficult process. Pipestone is quarried, or taken from out of the ground, by first digging through the grass and soil and then breaking up 10 or more feet of the hard Sioux Quartzite. Then 1 to 1½ feet of pipestone is removed in sheets of about 4 inches thick. The quarriers will use this stone to carve pipes and other small crafts. Today only American Indians are allowed to quarry, and then only with a permit. American Indians from many different tribes come here to quarry pipestone.