Flint is a hard, sedimentary cryptocrystalline form of the mineral
quartz, categorized as a variety of chert. It occurs chiefly as
nodules and masses in sedimentary rocks, such as chalks and
limestones. Inside the nodule, flint is usually dark grey,
black, green, white or brown in colour, and often has a glassy or waxy
appearance. A thin layer on the outside of the nodules is usually
different in colour, typically white and rough in texture. From a
petrological point of view, "flint" refers specifically to the form of
chert which occurs in chalk or marly limestone. Similarly, "common
chert" (sometimes referred to simply as "chert") occurs in limestone.
2.1 Tools or cutting edges
2.2 To ignite fire or gunpowder
2.2.2 Comparison with ferrocerium
2.3 As a building material
3 See also
5 External links
The exact mode of formation of flint is not yet clear, but it is
thought that it occurs as a result of chemical changes in compressed
sedimentary rock formations, during the process of diagenesis. One
hypothesis is that a gelatinous material fills cavities in the
sediment, such as holes bored by crustaceans or molluscs and that this
becomes silicified. This hypothesis certainly explains the complex
shapes of flint nodules that are found. The source of dissolved silica
in the porous media could be the spicules of silicious sponges.
Certain types of flint, such as that from the south coast of England,
contain trapped fossilised marine flora. Pieces of coral and
vegetation have been found preserved like amber inside the flint. Thin
slices of the stone often reveal this effect.
Puzzling giant flint formations known as paramoudra and flint circles
are found around Europe but especially in Norfolk, England on the
beaches at Beeston Bump and West Runton.
Flint sometimes occurs in large flint fields in
Jurassic or Cretaceous
beds, for example, in Europe.
Tools or cutting edges
Flint was used in the manufacture of tools during the
Stone Age as it
splits into thin, sharp splinters called flakes or blades (depending
on the shape) when struck by another hard object (such as a
hammerstone made of another material). This process is referred to as
In Europe, some of the best toolmaking flint has come from Belgium
(Obourg, flint mines of Spiennes), the coastal chalks of the
English Channel, the Paris Basin, Thy in
Jutland (flint mine at Hov),
the Sennonian deposits of Rügen,
Grimes Graves in England, the Upper
Cretaceous chalk formation of
Dobruja and the lower
Cenomanian chalky marl formation of the Moldavian Plateau
(Miorcani flint) and the
Jurassic deposits of the
Kraków area and
Krzemionki in Poland, as well as of the
Lägern (silex) in the Jura
Mountains of Switzerland.
Flint mining is attested since the
Palaeolithic, but became more common since the
culture, Funnelbeaker culture).
To ignite fire or gunpowder
Assorted reproduction firesteels typical of Roman to Medieval period
When struck against steel, a flint edge produces sparks. The hard
flint edge shaves off a particle of the steel that exposes iron, which
reacts with oxygen from the atmosphere and can ignite the proper
tinder. Prior to the wide availability of steel, rocks of pyrite
(FeS2) would be used along with the flint, in a similar (but more
time-consuming) way. These methods are popular in woodcraft,
bushcraft, and amongst people practicing traditional fire-starting
A later, major use of flint and steel was in the flintlock mechanism,
used primarily in flintlock firearms, but also used on dedicated
fire-starting tools. A piece of flint held in the jaws of a
spring-loaded hammer, when released by a trigger, strikes a hinged
piece of steel ("frizzen") at an angle, creating a shower of sparks
and exposing a charge of priming powder. The sparks ignite the priming
powder and that flame, in turn, ignites the main charge, propelling
the ball, bullet, or shot through the barrel. While the military use
of the flintlock declined after the adoption of the percussion cap
from the 1840s onward, flintlock rifles and shotguns remain in use
amongst recreational shooters.
Comparison with ferrocerium
Flint and steel used to strike sparks were superseded by ferrocerium
(sometimes referred to as "flint", although not true flint,
"mischmetal", "hot spark", "metal match", or "fire steel"). This
man-made material, when scraped with any hard, sharp edge, produces
sparks that are much hotter than obtained with natural flint and
steel, allowing use of a wider range of tinders. Because it can
produce sparks when wet and can start fires when used correctly,
ferrocerium is commonly included in survival kits.
Ferrocerium is used
in many cigarette lighters, where it is referred to as "flint".
As a building material
Flint, knapped or unknapped, has been used from antiquity (for example
at the Late Roman fort of Burgh Castle in Norfolk) up to the present
day as a material for building stone walls, using lime mortar, and
often combined with other available stone or brick rubble. It was most
common in parts of southern England, where no good building stone was
available locally, and brick-making not widespread until the later
Middle Ages. It is especially associated with East Anglia, but also
used in chalky areas stretching through Hampshire, Sussex,
Kent to Somerset.
Flint was used in the construction of many churches,
houses, and other buildings, for example the large stronghold of
Framlingham Castle. Many different decorative effects have been
achieved by using different types of knapping or arrangement and
combinations with stone (flushwork), especially in the 15th and early
Close-up of the wall of the Roman shore fort at Burgh Castle, Norfolk,
showing alternating courses of flint and brick
Elaborate 15th century flint and limestone flushwork at Long Melford
A typical medieval wall (with modern memorial) at Canterbury Cathedral
– knapped and unknapped ("cobble") flints are mixed with pieces of
brick and other stones
Thetford Priory show flints and mortar through the whole
depth of the wall
Elaborate patterned flushwork at top (restored in the 19th century)
and flint and limestone chequers below. Norwich Cathedral
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).
Flint pebbles are used as the media in ball mills to grind glazes and
other raw materials for the ceramics industry. The pebbles are
hand-selected based on colour; those having a tint of red, indicating
high iron content, are discarded. The remaining blue-grey stones have
a low content of chromophoric oxides and so are less deleterious to
the colour of the ceramic composition after firing.
Until recently flint was also an important raw material in clay-based
ceramic bodies produced in the UK. In preparation for use
flint pebbles, frequently sourced from the coasts of South-East
England or Western France, were calcined to around 1,000 °C.
This heat process both removed organic impurities and induced certain
physical reactions, including converting some of the silica to
cristobalite. After calcination the flint pebbles were milled to a
fine particle size. However, the use of flint has now
been superseded by quartz. Because of the historical use of flint,
the word "flint" is used by some potters, especially in the US, to
refer to siliceous materials that are not flint.
Flint bracelets were known in Ancient Egypt, and several examples have
Striped flint is today in use as a gemstone as well.
While flint may be used in fire-lighting, it should not be exposed to
excessive heat, as from a fire. Due to uneven expansion, flint may
fracture, sometimes violently, during heating. This tendency to
fracture is enhanced by the fact that most samples of flint contain
impurities that may expand to a greater or lesser degree than the
surrounding stone. This tendency to fracture is similar, but not
identical, to the tendency of glass to shatter when exposed to
To combat fragmentation, flint/chert may be heat-treated, being slowly
brought up to a temperature of 150 to 260 °C (300 to
500 °F) for 24 hours, then slowly cooled to room temperature.
This makes the material more homogeneous and thus more "knappable" and
produces tools with a cleaner, sharper cutting edge.
Nodule (geology) not to be confused with concretion
Ancient Egyptian flint jewellery
Clovis Points, archaeological artefacts of the
Clovis culture in New
Grimes Graves, a prehistoric flint mine in Norfolk, England
Flint Ridge State Memorial, a Native American flint quarry in Hopewell
Township, Licking County, Ohio, US
Quartz Information – Webmineral.com (page contains java
applets depicting 3d molecular structure)
Chert – quartzpage.de
^ a b The Flints from Portsdown Hill Archived 13 November 2007 at the
Chert Authentic Artefacts Collectors Assn. Archived 17
August 2004 at the Wayback Machine.
^ Museums.norfolk.gov.uk Archived 12 October 2007 at the Wayback
Flint Mines of Petit-
Spiennes Official web site
^ "Fire from Steel – Custom forged fire steels from Roman through
Fur Trade time periods". Angelfire.com. Retrieved 2013-07-21.
^ Bush, Darren. "Traditional Firestarting Part I: How to Make Fire
Flint and Steel". Manly Skills, Self-Reliance, Survival. Art of
Manliness. Retrieved 27 July 2015.
^ "Do you have 5 Ways to Make Fire?". Survival Cache. Retrieved 27
^ "Thoroughly Modern Milling" J.D. Sawyer. American
Bulletin 86, No.6. 2007.
^ "Ceramics: Physical And Chemical Fundamentals" H. Salmang & M.
Francis. Butterworths. 1961.
^ "Notes on the Manufacturer of Earthenware" E.A.Sandeman. The
Technical Press Ltd. 1921 .
^ "Changes & Developments of Non-plastic Raw Materials", Sugden,
A. International Ceramics Issue 2, 2001.
^ "Whitewares: Production, Testing And Quality Control." W.Ryan &
C.Radford. Pergamon Press. 1987.
^ "Use Of
Flint In Ceramics, Industrial Ceramics No.885, 1993.
^ "Silica". Oelef Heckroodt,
Ceramic Review No. 254, March/April 2012,
Calcination Of Flint. Part 2: Continuous Process In A
Vertical-Shaft Kiln." M. Manackerman & E.Davies. Research Paper
Ceramic Research Association, 1952.
^ "Changes & Developments of Non-plastic Raw Materials", A.Sugden.
International Ceramics Issue 2, 2001.
Ceramic Glazes. 3rd edition. Parmelee C. W. The Maple Press Company.
1973; Dictionary of Ceramics. 3rd edition. A.Dodd. The Institute of
Materials. 1994; The Potter's Dictionary of Materials and Techniques,
F.Hamer and J.Hamer, London, A & C Black, 2004.
Flint And Silica. C.M. Marsh. Proceedings of the American Ceramic
Society Annual Meeting 1978; Materials, Equipment & Whitewares
^ "Stoneware Clay Body Formulas. Part 2: The Perfect Body." J. Zamek.
Ceramics Industry 155, No. 10. 2005.
^ Graves-Brown, Carolyn. "AB29
Flint bracelet". Swansea University.
Archived from the original on 29 October 2012. Retrieved 13 January
^ "Building a cooking fire". Scout Notebook. 2001. Archived from the
original on May 25, 2009. Retrieved January 30, 2018.
Wikimedia Commons has media related to Flint.
Look up flint in Wiktionary, the free dictionary.
Flint Architecture of
East Anglia Book by Stephen Hart
Flintsource.net European Artefacts – detailed site
Flint circles and paramoudra – Beeston Bump
Paramoudras and flint circles photograph collection
Winchester Cathedral Close
Flint and the Conservation of
Flint Buildings Introduction to the
historical use of flint in construction and the repair and
conservation of historic flint buildings
Minimum ignition energy
Burning glass (Solar Spark Lighter)
Control of fire by early humans
Native American use of fire