Stone arrowheads were invented thousands of years ago.
Stone arrowheads were used for hunting and warfare for thousands of years until eventually replaced by metal. Today, making, and even using, stone arrowheads is an increasingly popular hobby. The best stones for arrowheads are brittle with a fine-grained, uniform texture free of imperfections such as fractures, cracks and fissures.
Stone arrowheads developed sometime in the late Paleolithic period when our ancestors discovered techniques for making tiny tools. This technology was used throughout the world until it was replaced by metalworking. Some groups, such as Native Americans, continued making stone arrowheads well into the 19th Century.
Flint and Chert
Flint is a variety of dark gray, black or dark brown quartz that forms in rounded nodules. Light gray flint is called chert. Stone age people began using flint and chert because this material is very hard but easily shaped by pressure exerted with simple tools. This technique gave tools a sharper edge than the pounding technique used to shape other stones. Later it was also used with small pieces of iron for starting fires and igniting gunpowder in firearms.
Obsidian is a naturally occurring glass created when lava cools very quickly. It is usually black but brown, red and greenish varieties occur. It was used for spear-points, arrowheads, knives and other tools. The Aztecs and other Mesoamerican cultures were still using obsidian when the Spaniards arrived in the 16th Century.
Quartzite is a metamorphic rock formed from heavily cemented grains of quartz, resembling sandstone. It is typically white, yellow, light brown or gray although other minerals may give it a purple, black or blue color. Sandstone and quartzite can be distinguished by the way they break. Quartzite breaks along the lines of constituent sand particles while sandstone breaks along the cementing materials between the sand.
Jasper is a dense, opaque form of quartz. It is colored by iron oxide and is usually red, yellow or brown. Today it is used primarily as gemstone for inexpensive jewelry and other ornaments, however, in ancient times it was one of many rocks used for tools and weapons.
Stone arrowheads and other tools are shaped with a 4-million year old technique called flint knapping A flint knapper begins an arrowhead with a technique called percussion flaking, which involves precisely breaking off flakes from a larger stone. When enough flakes are collected, they are given a sharp edge with a technique called pressure flaking. During pressure flaking, pressure is applied to the stone with a small tool until chips break off. When the flake has the proper shape, it is finished by carving out a notch on either side so that it can be attached to a shaft.