Flint facts for kids
Flint, also called flintstone, is a very hard rock. It is made of a material called silica.
You can often find flint in layers inside softer rocks like chalk and other types of limestone.
When chalk gets worn away by weather and water (this is called erosion), the hard flint pieces are left behind. They often become smooth pebbles on a shingle beach. Sometimes, these pebbles can get stuck together again to form a new rock, like a puddingstone. This means they become a sedimentary rock for a second time!
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What is Flint?
Flint is a special type of quartz mineral. It's called "cryptocrystalline," which means its crystals are so tiny you can't see them even with a strong microscope. It is a kind of chert.
Flint usually appears as bumpy, lumpy shapes inside chalk and some limestones. Inside, flint is often clear enough to let some light through (we call this translucent). It can be many different colors. The outside layer of a flint lump is usually white and feels rough.
How People Have Used Flint
Flintstones often look rough on the outside. But if you break one, the inside looks like dark glass and has a very sharp edge. Because of this, flint has been one of the most useful types of stone for humans throughout history.
Early Tools
Early humans and their ancestors used flint for more than three million years. Some of the oldest stone tools ever found were made of flint. They were discovered at Lake Turkana in Kenya and are about 3.3 million years old. This is even older than the first known fossils of our own human group, Homo, which are about 2.8 million years old.
When flint is broken, it creates a very sharp edge. This sharp edge was perfect for using as a knife or a scraper. Early humans used these tools to cut meat, scrape animal hides, and shape wood.
Making Fire
Flint can also make sparks. If you hit flint against a material that contains iron, like pyrite or steel, it creates a spark. For many centuries, this was a main way for people to start fires.
People would carry a small container called a "tinder box." This box held some tinder (like sawdust, cloth, grass, or bark) along with a piece of flint and pyrite or steel. They would strike the flint and iron together to make a spark. The tinder would catch the spark and help start a fire. Later, flint was used to make sparks to fire guns. A gun that used flint to create a spark was called a "flintlock" gun.
Building with Flint
In some countries, flintstones are used for building. In England, builders often "knapped" the flintstones. This means they broke them open to show the smooth, dark inside. This made the buildings look much nicer than if they had used the dull, lumpy outside of the stones. You can see examples of this in old churches, like the tower of Long Melford Church.
Gallery
Related pages
Images for kids
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A piece of flint, about 9-10 cm long, weighing 171 grams
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Tiny fossil algae and silica crystals inside flint. Image width: about 5 mm.
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A pebble beach made of flint rocks that broke off nearby chalk cliffs, Cape Arkona, Rügen, Germany.
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A Neolithic flint axe, about 31 cm long
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A ferrocerium “flint” spark lighter in action
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Different types of firesteels, like those used from Roman times to the Middle Ages.
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A flint church – the Parish Church of Saint Thomas, in Cricket Saint Thomas, England. The neatly shaped flints are about 3 to 5 inches (8 to 13 cm) tall.
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A close-up of a wall from the Roman shore fort at Burgh Castle, England. It shows layers of flint and brick.
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A typical medieval wall at Canterbury Cathedral. It mixes shaped and unshaped flints with pieces of brick and other stones.
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The ruins of Thetford Priory show flint and mortar throughout the wall.
See also
In Spanish: Sílex para niños
