--- Minerals list
--- Silicates index
--- Rocks index
|Flint or Chert
|From "flint" (Danish)
Chert's derivation is unknown
Opaque, grey, brown or black, sometimes with a chalky outside. Flint should only be used for the black variety. The rest is chert.
Flint is the commonest silicate. In fact, the specimens above are not part of my collection. I just wandered round my garden finding them!
In the Stone Age, people used flaked flint to make tools. As you can see above, flint breaks off in chips, and a skilled knapper can make well-shaped axes, arrow heads and other tools.
Tinder boxes and early guns had flints to produce a spark.
Larger pictures of Flint:
These specimens are natural. The one on the right shows a conchoidal fracture. Flint doesn't break into smooth cleavage planes. Instead it fractures. A conchoidal fracture has curved lines, rather like a sea-shell (which is where the word "conchoidal" comes from).
Pictures of Flint used in buildings:
Flint is sometimes used as a building material. It is not particularly suitable, as it is difficult to work, and only comes in small stones. However in parts of East Anglia, in England, there is no other local building stone. The buildings below are mostly in Norwich and show different ways of using flint. One property of flint is that it does not wear, as it is so hard. So it is difficult to see how old these buildings are!
Sometimes the flint is mixed in with other stones and rubble.
Sometimes it is used as half-nodules, split in half but with no other shaping, so still keeping the roughly round shape.
Sometimes it is split into rectangular shapes, almost like bricks.
Sometimes it is used with other stone to produce very attractive filler effects.
A building in Cambridge Mill Road cemetery.
Some cottages in Margate Old Town.