The use of the peace pipe was held sacred by Indians. Usually it was used in ceremonies of religious, political, or social nature. The decorations on the pipe's bowl and stem, and even the method of holding or passing the pipe on to the next person, held great ceremonial significance. The pipe was never laid on the ground. To smoke it was a signal that the smoker gave his pledge of honor. It is also believed that the smoke made one think clearly and endowed him with great wisdom. In a treaty ceremony, the pipe usually was passed around to everyone, even before the speeches were made and the problems discussed. Some pipes were made out of wood, clay or bone. But the most popular were made out of pipe stone (catlinite) mined in the pipestone quarries of Minnesota. These red stone quarries were considered sacred by the Dakotas (Sioux), and were traditionally neutral ground for all tribes. Indians traveled many miles to get this pipestone, and it was a medium of barter between various tribes. The stone was so soft that it could be cut and worked into designs with a knife when freshly quarried. Some pipes were inlaid with lead. It is said that some of the Indian raids on small western town newspapers were made by the Indians to get type lead with which to inlay their pipes.