What Kind of Rocks Make Arrowheads?
29 SEP 2017
Cultures throughout history have carved rocks to form weapons including arrowheads. Native Americans in particular are famous for making arrowheads from stone. There were several types of rock they used to make these sharpened methods of defense and hunting.
Bows and arrows were invented during the Middle Stone Age, also known as the Mesolithic Era, circa 10,000 to circa 5,500 B.C. The invention of a long-range weapon allowed for primitive humans to begin hunting more efficiently. Arrowheads underwent minimal evolution through that time. The workmanship improved, but the main concept of chipping the edges from rock until flat and light enough to fly, and sharp enough to pierce animal hide, remained the same. The chipping of stones, called knapping, is still practiced today by enthusiasts.
Obsidian is known for its characteristic glossy appearance and smooth texture. It is formed from the lava flow from a volcanic eruption and comes in many colors, but black and brown are the most common. Unlike other rocks, obsidian is not considered a mineral because of its noncrystalline, glass-like structure. This rock was a common material for arrowheads due to its ability to chip easily and sharpness. When chipped, obsidian has both the appearance and the slicing ability of broken glass. It is also a very hard rock, so it is unlikely to shatter on impact with its target, whether human or animal.
Flint was perhaps the most commonly used rock in making arrowheads throughout history. It was among the first stones used to create arrowheads in the Mesolithic era of human development. Along with arrowheads, flint was also used to create spear points, cutting utensils and fire when struck with steel in later eras. Flint is a sedimentary rock that has the potential to break into small fragments with sharp edges. This means that, along with cutting, flint is ideal for scraping objects as well. It also is a hard stone with no definite cleavage, which means that it can shaped with relative ease.
Quartz was rarely used to create arrowheads, at least in comparison to flint, its more grainy incarnation, and obsidian. Therefore, any arrowhead made from a pure quartz that is found in good condition is considered rare. Quartz registers as a seven on the Mohs scale of hardness, meaning it is a fairly durable material that would be suitable for arrowhead shaping. The most abundant mineral in the world, quartz today is used to make glass and in the petroleum industry.