Flint

A flintstone

Chalk cliffs at Dover cliffs. The slanting dark lines in the chalk are flint.

Flint handaxe from Hoxne, England. This is the first published picture of a handaxe in archaeological history.^[1] The handaxe was not a weapon; it was a tool used in butchering the carcasses of mammals.

Flint, or flintstone, is a kind of sedimentary rock, made of silica.

Bands of flint are found embedded in chalk and other kinds of soft limestone.

When the chalk is eroded, the hard flint nodules survive as pebbles on a shingle beach. It may happen that the pebbles later get cemented into another rock, such as a puddingstone. In this way, they make up a sedimentary rock for the second time.

Technical description

Flint is a cryptocrystalline (means you can't see the crystals) form of the mineral quartz.^[2]^[3] It is a variety of chert. It occurs as a line of knobbly masses in chalk and some limestones.^[4]^[5] Inside the nodule, flint is usually translucent, and can be various colours. A thin layer on the outside of the nodules is usually different in colour, typically white and rough in texture.^[6]

Uses

Flintstones often have a rough lumpy surface but when they are broken, they look like dark glass. It has been one of the most useful types of stone to humankind.

Flint was used by hominins for over three million years. Stone tools found at Lake Turkana in Kenya, are dated as 3.3 million years old. This predates the genus Homo by half a million years. The oldest known Homo fossil is 2.8 million years old compared to the 3.3 million year old stone tools.^[7]

When flintstones are broken, they have a sharp edge which could be used as a knife, or a scraper. When flint and an iron-containing material such as pyrite or steel are hit together, they can make a spark.^[8] For many centuries, flint was one of the main ways for people in many countries to make fire. People would carry a little box called a "tinder box" which had some tinder along with flint and pyrite or steel. The tinder was used to catch the spark and start a fire. Tinder could be sawdust, cloth, grass or bark. Flints were later used to make a spark to fire a gun. A gun that used flint was called a "flintlock" gun.

Flintstones are used in some countries for building. In England the flintstones used for building were often "knapped" which means they were broken to show the inside, like the stones used for the tower of Long Melford Church (below). This gave a better finish to the building that the dull knobbly stones would have made.

Gallery

A flint dagger nearly 5000 years old, from Germany
A "flint-lock" on a gun
Flint & brick wall
The flintstone wall of a building in England
Holy Trinity Church at Long Melford has a tower of knapped flint.

Flint Media

A piece of flint 9–10 cm (3.5–3.9 in) long, weighing 171 grams
Silicified remains of algae and silica pseudomorph after halite in flint. Pebble of Loire near Marcigny, France. Image width: about 5 mm.
Pebble beach made up of flint nodules eroded from the nearby chalk cliffs, Cape Arkona, Rügen, northeast Germany.
Neolithic flint axe, about 31 cm long
A 12,000 year old Folsom tradition spearpoint about 76 mm (3 in) long
A ferrocerium "flint" spark lighter in action
Assorted reproduction firesteels typical of Roman to Medieval period
Bottle kilns traditionally used for calcining flint
A flint church – the Parish Church of Saint Thomas, in Cricket Saint Thomas, Somerset, England. The height of the very neatly knapped flints varies between 3 and 5 inches (7.6 and 12.7 cm).
Close-up of the wall of the Roman shore fort at Burgh Castle, Norfolk, showing alternating courses of flint and brick