What Is Flint?
Flint is one of the various forms of silica, which is among the common materials making up the largest parts of rocks. Some other forms of silica are quartz, opal, chalcedony, agate, jasper and onyx. Flint (essentially, silica with some water, a little lime, oxide of iron and, occasionally, carbon) can be gray, grayish-white, smoke-brown, brownish-black, red or yellow.
Flint is very durable and can be found along streams and beaches. It occurs as layers in other sedimentary rocks. Because it flakes and can easily be chipped into a sharp cutting edge, flint was used by prehistoric man to make axe heads, arrow heads, knives and other such sharp-edged implements. The study of implements from the Paleolithic, or Old Stone Age, and the Neolithic, or New Stone Age, has helped us understand how people lived then.
During the Stone Age access to flint was so important for survival that people would travel or trade to obtain flint. Flint Ridge in eastern Ohio was an important source of flint and Native Americans extracted the flint from hundreds of quarries along the ridge. This “Ohio Flint” was traded across the eastern United States and has been found as far west as the Rocky Mountains and south around the Gulf of Mexico.
Another important property of flint is its ability to generate sparks of hot material when it is struck against steel. This property allows flint to be used as a fire-starter. Skilled people can use a piece of flint, a piece of steel, and a little tinder to quickly start a fire.
Early firearms, such as a flintlock, had a piece of flint attached to a spring-loaded hammer that was released when the trigger was pulled. The hammer struck a piece of steel known as a “frizzen” to create a shower of sparks that ignited a small pan of powder. That touched off the primary charge which exploded to propel the ball down the barrel.
The name “flint” has been so closely associated with starting fires that man-made materials used to produce sparks in cigarette lighters and survival kits have been given the name “flints.”
Flint is a very durable material that accepts a bright polish and often occurs in attractive colors. It is occasionally cut into cabochons, beads, and baroque shapes for use as a gemstone. It is also used to produce tumbled stones in a rock tumbler.
Most people have heard of a gem material called “jasper”. Jasper is an opaque variety of cryptocrystalline quartz. It obtains its color and opacity from a large amount of included mineral particles. Flint and jasper are similar materials and both are varieties of a gem material known as “chalcedony”
Where flint is abundant it is sometimes used as a construction material. It is very durable and resists weathering better than almost any other natural stone. It is common to see walls, homes, and larger buildings that are built partially or entirely with flint as a facing stone in southern England and many parts of Europe.