cherts

chert is often used to make tools in prehistoric times.

the geology class studied the formation of chert.

chert can be found in many sedimentary rock layers.

archaeologists often discover chert artifacts at dig sites.

chert is known for its sharp edges when fractured.

some native american cultures relied heavily on chert for tool-making.

the color of chert can vary from gray to brown.

chert often contains fossils of ancient marine life.

many prehistoric people used chert to create arrowheads.

chert can be polished to create beautiful decorative items.