Flint
Limestone and marl wall
Nature has always provided man with everything he needs to live - water, air, plant and animal products on which he feeds, as well as rocks and minerals. From flint, in the Ancient Palaeolithic, to the current “coltan”, passing through clay, ores of gold, copper, tin, iron and many others, man had the skills of, over time, extracting from geodiversity everything he knew how to use. or turn to your advantage.
With a Latin root, flint is the name of an essentially siliceous sedimentary rock, that is, a silicite, as it is said in modern petrographic nomenclature, and is the etymology of the words silicon, the chemical element, silica, silicon dioxide (SiO2) and silicon, a well-known material in reconstructive surgery. Originally, it also meant stone and pebble. Being stone, its use by our remote ancestors, in the production of various utensils, gave its name to the period of Prehistory referred to as the Stone Age.
In popular terms it is the flint, that is, the stone capable of producing sparks or sparks when struck between itself or by iron. Due to this capacity, it also received the name of firestone, having been used, above all, in the 17th and 18th centuries, in artillery pieces, muskets, blunderbusses and pistols.
The flint was described by the French authors as a silicification within a very fine-grained and not very cohesive limestone from the Upper Cretaceous (which can be seen in the white and steep French and English cliffs that flank the English Channel) to which the name of chalk and which is interpreted as a product of diagenesis and, therefore, subsequent to the sedimentation of the referred limestone.
During this process, the silica generates nodules or concretions (from a few centimeters to a few decimeters) distributed according to the bedding joints, drawing strings and also along fractures that allow the progression of the silica.
With almost 100% silica, flint is a very compact, homogeneous, hard but fragile rock, with a characteristic conchoidal fracture, a feature skillfully used by our most remote ancestors. The expression Stone Age, current in many texts, alludes to this type of fracture, which is also typical of macrocrystalline quartz (namely, hyaline and smoked), jasper, volcanic glass (obsidian) and quartzite.
Some examples of flint
Uses
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 knapping.[9]
Flint mining is attested since the Paleolithic, but became more common since the Neolithic (Michelsberg culture, Funnelbeaker culture). 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 Danube (Balkan flint), the 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.
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. Heat treating was known to stone age artisans.
To ignite fire or gunpowder
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 remain popular in woodcraft, bushcraft, and amongst people practising traditional fire-starting skills
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 those parts of southern England where no good building stone was available locally, and where brick-making was not widespread until the later Middle Ages. It is especially associated with East Anglia, but also used in chalky areas stretching through Hampshire, Sussex, Surrey and 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 16th centuries. Because knapping flints to a relatively flush surface and size is a highly skilled process with a high level of wastage, flint finishes typically indicate high status buildings.
ref: wikipedia, Sopa de Pedra
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