Rock Cycle - Rocks (4A)
Post Lab 

  • Exploring the uses of rocks in the Native American culture
  • Discovering why rocks were important in everyday life.
  • flint
  • mortar
  • pestle
  • tools
  • Display - Indian Rocks
  • arrowheads

Students study rocks in Native American culture.


Early humans did not have many materials available to fashion tools. Steel, iron, plastic, and many other materials were not invented or discovered until modern times. The only materials available were trees, rocks, plants, minerals, and animal remains. Rocks and minerals were important because many types are naturally hard.

Some minerals were ground up and mixed with animal fat for use as face paint or to create colors on cave walls. The red in many cave paintings used hematite (an iron oxide mineral.) Minerals were also used as jewelry, much as they are today.

Rocks were converted into useable tools. For example, large flat rocks were used as grinding stones (mortar and pestle). Wild grains were crushed on them to produce flour. Many of these rocks were well-cemented sandstone or igneous rocks (basalt in particular). Long round rocks were then used to roll the grain mixture into flattened dough, which could be easily cooked over a fire. Rocks, like obsidian or chert (composed of quartz), could be also fashioned into weapons. Arrowheads were traditionally made from rocks like obsidian, which could be sharpened enough to pierce the skin of an enemy or prey. Heavier rocks were used as blunt instruments.

Even pottery requires clay from a pure mudstone. Fine grained feldspar (a mineral) is also used in making some pottery better than others.

  1. Discuss some of the uses of the rocks in the Indian Rocks display. Quartz and flint were used to make fire. Flint, agate, and obsidian were used for knives. Sandstone, basalt, and granite were used for mortars and pestles. Sulfur was used as a medicine. Early humans also used ground minerals as pigment in rock paintings.
  2. Instruct the students to imagine that they are early Native Americans living in this country. You may want to list some of the Indian tribes such as the Navajo, Hopi, Ohlone, Cherokee, Cheyenne, or Apache. Have the students try to imagine what mineral and rock resources they would have available, and how they would use them.
  3. If you have information on the Native Americans in your area, we suggest you find out how they used rocks and minerals in their culture. A local museum or college can provide information.

[Back to Rock Cycle Grid]   [Back to Rocks (4)]