Instructions
Examine the shape of the stone projectile. An arrowhead's shape is often a clue to its age. For example, archaeologists believe that most fluted spear tips found between the Rocky Mountains and the East Coast were created between 11,300 and 10,200 years ago. Arrowheads with side notches, meanwhile, were created thousands of years later. Nearly all Paleo-Indian cultures eventually adopted unnotched triangular tips, according to the Mississippi Valley Archaeology Center at the University of Wisconsin-La Crosse.
Examine the type of material used to make the arrowhead. Knowing the type of rock or base material can help pinpoint key identifiers. If you find an arrowhead made of chert, for example, you can assume it originated in areas with large deposits of the sedimentary rock. A little investigation into the geology of the area can possibly help you locate the arrowhead's point of origination, an insight that can lead to some enjoyable speculation about the culture that created it. Arrowheads in later times were created from an ever-broadening variety of materials, especially as cultures clashed in the 19th century. Hobbyist collectors who maintain the website WesternArtifacts.com list one example made from red railroad glass -- a giveaway that the arrowhead was created in more modern times.
Verify that both sides of the point show chiseled markings, as an indicator of authenticity. Arrowheads and stone projectiles that appear worked only on one side are often modern creations sold in gift shops.
Record your findings. Use a map or a journal to record the locations where the stone projectiles were found. As your records grow, you will find this helpful in identifying future findings.