Arrow heads, scrapers, rock knives and saws which were left by the
Indians who formerly lived in Missouri may be found in moderate
abundance in many parts of the state. Usually these artifacts are chert
in its various colors, white, gray, mottled, reddish, or black (flint).
See the discussion of chert on page 34. Chert, because of its conchoidal
fracture, lack of cleavage, resistance to chemical weathering, and
superior hardness, is an exceptionally useful rock for making tools and
weapons.
Hammers and axes of basalt, and arrow heads of rhyolite are less
abundant than the chert artifacts.