Feuerstein , and Flint or Silex , is a siliceous rock and consists almost exclusively of silicon dioxide (SiO 2 ). The silicon dioxide is in the form of very fine-grain (microcrystalline) quartz ( chalcedony ) and mogánite and / or in the form of opal . There are also accessory minerals, such as hematite , which can give the rock a certain color. The term flint is preferably given to those formations that have arisen diagenetically in fine-grain marine limestones . The name flint refers to its historical significance for making fire . The "flints" that are used in modern lighters, however, are made of a metal alloy (cerium iron, see Auermetall ) and are called flints .
Origin and properties
The origin of flint is still not fully understood. Solutions containing silicic acid presumably cause carbonates to be displaced during diagenesis (compaction and transformation processes during rock formation) . Relics of skeletons from pebbles and diatoms in flint bulbs prove the organic origin. Flint consists primarily of fibrous chalcedony , similar to jasper (a cryptocrystalline, but not fibrous, but granular quartz , with a grain size smaller than 1 micrometer ). The flint diagenesis usually runs via Opal -A (amorphous), Opal-CT (like chalk easy to work on) to flint.
The dehydration of the silica takes place from the inside out, which means that the flint bulbs often have an onion-like structure. The porous, light-colored outer layer (the so-called bark or cortex) is often clearly recognizable. It is the diagenetic precursor to flint, (SiO 2 · nH 2 O), the so-called Opal-CT. This is easy to edit. Converting Opal CT to flint takes millions of years. The outer layers can absorb a small amount of water, which promotes weathering of the surface.
Flint has an isotropic or amorphous structure, which means that it lacks a preferred orientation. If high pressure is exerted slowly or suddenly on a point of the flint, the kinetic energy is absorbed by the rock and spreads out in a concentric cone-shape from the point of impact. If the impact energy is sufficiently high, the rock is split by the propagating impact waves. The resulting break front usually has a shell-like shape, as can also be observed on broken glass.
In the area of a fracture point, the flint also has impact waves, the Wallner lines . They arise mainly from deliberately split off parts of the stone, which are known as tees .
Fresh flint usually has a black to gray color. Weathering makes it increasingly milky; in addition, yellowish to brownish discolouration caused by iron oxide can occur. Red flint is rather rare; it can be found in Central Europe, for example, on the beaches of the dune of Heligoland . The red color is the result of trivalent iron compounds (for example hematite ). The red flint comes from the underwater chalk of the Turons (Upper Chalk) in the area around the island. On Heligoland, the red Heligoland flint is processed as a gemstone and sold, as a polished disc, cut as a ring stone ( cabochon ) or drawn in a spherical shape as a chain.
Distribution in Europe
Flint deposits are found in numerous Jurassic and Cretaceous deposits. Most of the tubers are up to 30 cm in diameter embedded in chalk deposits. There are also plates with a thickness of up to 20 cm. Through later rearrangement processes, they also find themselves removed from their original stratigraphic context. For example, flint stones are very common in ice age sediments as a component of ground and terminal moraines and also within meltwater deposits.
Distribution in Germany
In Germany, in the mother rock, the flint occurs mainly in the chalk of Helgoland Düne , Rügen , Lägerdorf (Schleswig-Holstein) and Hemmoor (Lower Saxony). Secondarily, it can be found in the entire north-central European distribution area, there also extremely enriched locally ( flint fields in the Steinfelder nature reserve in the Schmalen Heide and extension ). In the mountains of southern Lower Saxony, flint can be found as Ice Age debris up to the edge of the Harz Mountains and in the Leine Valley to around Freden , north of the so-called flint line . In addition, it occurs in white weathered form in the tertiary sands of the Miocene of the Solling and is known as chert from the Middle Muschelkalk ( Göttingen to Einbeck ), Korallenoolith / Heersum layers ( Thüster Berg ) and Hilssandstein.
Flint also occurs in other areas of Germany, albeit less often, but was also found and used there. Tons of flint blocks that were probably formed in marl can be found on Flinsberg near Oberrot , Baden-Württemberg .
Flint distribution in early and prehistory
The distribution map of the Silex from the Schaffhausen-Singen region shows that the varieties there were almost exclusively passed on to settlements of the Hornstaad group of the Pfyner culture , which was located in the Upper Rhine - Lake Constance region. These raw materials only rarely reached the area on Lake Zurich , where the Cortaillod culture was also at home. The settlements on the Zurich lakes, on the other hand, were primarily supplied with flint from the Lägern region or from the Olten area . Thus, the distribution of raw materials seems to be related to the cultural area.
The qualitatively equivalent tubers from the Lägernsilex are significantly larger than the Schaffhauser Silex tubers, making them suitable for the production of larger devices. Despite this advantage, however, Lägernsilex arrived around 4000 BC. BC not in significant quantities across the cultural border to Lake Constance.
This suggests that silica raw materials were not traded commercially in the study area, but that the distribution took place on a different basis. The relationship between the main area of distribution of the raw material and the archaeological cultural areas suggests that it was distributed according to certain social premises. A ceremonial exchange of raw materials, semi-finished and finished products is conceivable, whereby the social aspect was in the foreground. Ethnologists have observed comparable forms in recent and sub- recent societies. There, the transfer of material goods and raw materials primarily serves to strengthen social and political ties. Similar conditions are evidently to be assumed for the older Neolithic in the northern Alpine foothills.
Around 100 prehistoric flint mines are known in Europe, Stone Age pits in which raw material for the manufacture of flint tools and weapons was extracted with the simplest means.
Because of its great hardness, its highly predictable cleavage and extremely sharp edges, flint was an important raw material in the Stone Age for making cutting tools and weapons. He achieved great importance with the discovery that you can generate sparks with his help.
Contrary to popular belief, hitting two flint stones cannot generate sparks for lighting a fire. This creates sparks, but they are not hot enough to start a fire. Instead, either iron (II) disulphide (FeS 2 ) in the form of pyrite (from ancient Greek πῦρ pyr = 'fire') or marcasite or steel is required as the second component .
A Stone Age “lighter” consisted of a flint, easily combustible powder or easily ignitable fiber (the tinder ), and pyrite or marcasite. The actual fire-generating stone is the pyrite / marcasite, from which small chips are chipped off by means of the flint, which are ignited by the impact energy and the frictional heat generated during impact - the sparks . Flint is not absolutely necessary as a striking stone , quartz or quartzite are also suitable.
With the help of flint and steel , sparks can also be made. The steel must have a comparatively high carbon content (1.5–2%); this can be found z. B. in the steel of a file (see: Feuereisen ). Analogous to the process with pyrite / marcasite, the stone scrapes off tiny chips from the steel, which ignite due to the heat generated. Until the advent of matches in the 19th century, steel and stone were the only common lighter . Therefore, attempts were made to keep the embers in the ovens overnight in order to save the laborious fire-fighting. In a modern gas or petrol lighter, the spark is struck with a friction wheel from a flint , the hardness of the friction wheel being greater than the iron-cerium alloy of the flint.
From the 16th to the 19th century flint served in flintlock weapons as an ignition aid. A small flint attached to the gun's cock hit a steel spur (battery) at high speed when the trigger was pulled. The resulting sparks ignited the black powder on the pan attached below, the flame of which spread to the black powder in the barrel, the combustion gases of which drove the bullet out of the barrel. Because of its earlier use in firearms, pierre à fusil (" Büchsenstein ", see also Füsillade ) is a synonym for silex in French .
Jewelry and amulets
Flint bulbs with a naturally formed hole, so-called "chicken stones" or "chicken gods ", were and are used particularly as talismans (for the theory of how the holes were formed, see Paramoudra ). It is still used as a gemstone today, as well as for a variety of decorative applications.
Especially in England, flint has been used as a building material for almost all types of buildings since ancient times. Today flint plays a subordinate role as a raw material. In road construction, it is mixed with the asphalt in ground form in order to improve the reflective properties of road surfaces. Finely ground it is used as an abrasive , but has been largely replaced by electric corundum .
In Russia there is an old, deeply rooted popular belief that the chemical nature of the black flint purifies water and makes it usable for human consumption. In pharmacies, flint fragments are sold in packs of 10, 50 or 150 g with precise instructions for use: wash off 50 g of flint debris, pour into a container with 5 l of water, leave for 3 days. Then the water can be used for drinking, cooking, washing, plants and aquariums. After 6 to 8 months, it is desirable to replace the flint stones.
Flint from the Baltic Sea ( Boltenhagen )
Ornamental knife from Gebel el-Arak , predynastic around 3300–3200 BC BC with ivory handle and flint blade
Fishtail dagger from Hindsgavl, Denmark
Prehistoric processing techniques
During the Stone Age, numerous techniques were developed and optimized to make tools or weapons from flint and other rocks , such as blades like knives or hand axes . This handicraft reached a high level of skill in many places (for example in Denmark ) in the late Neolithic . The high point of the art of processing can be found among the Maya in the irregular flint stones. Other varieties such as obsidian or chalcedony were also processed .
Some of the essential Stone Age techniques for working flint are briefly explained below. Only techniques of the so-called basic shape production (or tee production) are presented here. This creates the two basic forms, core and tee .
Direct hard technique
The flint (core) is processed directly with a suitable hammer stone ( e.g. quartzite rubble ). This technique usually results in relatively large discounts .
The picking technique is a variant of the direct hard technique. The striking stone is made of very hard rock (for example, a flint stone) and is hit with a high impact frequency on the surface of the workpiece . Here the stone is formed by removing a large amount of tiny particles. These traces of impact are clearly visible.
Direct soft technique
Here, too, the workpiece is machined with direct impacts. However, a softer material (e.g. antler mallet) is used as a striking device. Separated haircuts are usually thin and slightly curved. This technique can also be used to make long, narrow cuts, so-called blades.
With the printing technique, the pressure is not suddenly applied to the flint, but slowly increasing until a tee is cut off. For this purpose, for example, wooden pressure rods with antler tips can be used. With a printing technique that uses the weight of the upper body, long, narrow blades can be created. Other printing techniques are suitable for creating a uniform surface, for example with daggers .
In the punching technique, an adapter made of antlers is used, which is hit with a mallet made of antlers. This technique enables a high level of energy to be applied to a specific point. In this way, very precise tees can be produced.
Other processing techniques
In addition to the striking techniques, other techniques were used to give the flint tools the desired shape or to optimize the surface and create sharpening devices.
With this technique, the flint is ground smooth on a hard, granular rock (e.g. a sandstone block). This method is documented with Neolithic stone axes of the funnel beaker culture and the spherical amphora culture . These were ground either completely or on both sides along the cutting edge.
Drilling techniques have been used for axes made of rock (e.g. basalt or amphibolite ) since the Neolithic . Flint is extremely hard and has therefore rarely been drilled. Quartz sand was used as drilling material. Flint axes and blades were initially only used in the hand, hence the term hand ax . Connected to a shaft , they were further developed into tools and weapons by clamping or tying them.
A procedure that does not shape the material but rather influences the material properties is tempering , ie the stone is exposed to heat.
- Kurt Altorfer: flint bulbs, drills, pearls. New insights into the use of the Schaffhausen silex deposits. In: AS. Archeology Switzerland. Vol. 33, No. 3, 2010, pp. 14-21, ( online ).
- Alexander Binsteiner : Prehistoric Silex Mining in Europe. Geological and geological studies. In: Bavarian history sheets . 62, 1997, pp. 221-229.
- Sabine Gayck: Prehistoric Silex Mining in Europe. A critical analysis of the current state of research (= contributions to the prehistory and early history of Central Europe. 15). Beier & Beran, Langenweißbach-Weissbach 2000, ISBN 3-930036-22-3 (also: Cologne, University, Master's thesis, 1993).
- Walter Leitner: The oldest silex and rock crystal mining traces in high alpine regions. In: Stefano Grimaldi, Jean Guilaine, Thomas Perrin (eds.): Mountain Environments in Prehistoric Europe. Settlement and mobility strategies from Palaeolithic to the Early Bronze Age (= Proceedings of the XV World Congress UISPP (Lisbon, 4-9 September 2006). Vol. 26 = BAR. International Series. 1885). Archaeopress, Oxford 2008, ISBN 978-1-407-30365-9 , pp. 115-120.
- Michael M. Rind (Ed.): Feuerstein. Stone Age raw material. Mining and processing technology (= Archaeological Museum of the City of Kelheim. Museum booklet. 3). Leidorf, Buch am Erlbach 1987, ISBN 3-924734-60-7 .
- Gerd Weisgerber , Rainer Slotta , Jürgen Weiner: 5000 years of flint mining. The search for the steel of the Stone Age. Exhibition at the German Mining Museum Bochum from October 24, 1980 to January 31, 1981. German Mining Museum, Bochum 1980, ISBN 3-921533-20-1 .
- English-language database on flint deposits in Europe
- Flint collection
- Chemistry and uses of flint
- "Flintknapper's Exchange" - English-language magazine for cutting flints (PDFs from 1978–79)
- ^ Karl Gripp : Geological history of Schleswig-Holstein. Wachholtz, Neumünster 1964.
- ^ Friedrich Schmidt, Christian Späth: Feuerstein types of the Upper Cretaceous Heligoland, their stratigraphic occurrence and their comparison with other occurrences in N.-W. Germany. In: Staringia. No. 6, 1981, ZDB -ID 186344-7 , pp. 35-38, ( natuurtijdschriften.nl ).
- ^ A b Matthias Leopold, Jörg Völkel: Neolithic flint mines in Arnhofen, southern Germany: a ground ‐ penetrating radar survey. In: Archaeological Prospection. Vol. 11, No. 2, 2004, ISSN 1075-2196 , pp. 57-64, doi: 10.1002 / arp.222 .
- ↑ a b Tobias L. Kienlin, Paweł Valde-Nowak : Neolithic transhumance in the Black Forest mountains, SW Germany. In: Journal of Field Archeology. Vol. 29, No. 1/2, 2004, ISSN 0093-4690 , pp. 29-44, doi: 10.1179 / jfa.2004.29.1-2.29 .
^ Gerhard H. Bachmann, Horst Brunner: North Württemberg. Stuttgart, Heilbronn and the surrounding area (= collection of geological guides. 90). Borntraeger, Stuttgart 1998, ISBN 3-443-15072-1 .
Dieter B. Seegis, Matthias Goerik: Lakustrine and pedogenic sediments in the marl marl (Middle Keuper, Upper Triassic) of the Mainhardt Forest (northern Württemberg). In: Annual reports and communications from the Upper Rhine Geological Association. NF Vol. 74, 1992, pp. 251-302, doi : 10.1127 / jmogv / 74/1992/251 .
- ↑ In July 2010, during excavations at the Lägern (between Dieldorf and Baden), traces of mining from the Stone Age (4000 BC) were discovered.
- ↑ Silex in the etymological online dictionary of the Center Nationale de Ressources Textuelles et Lexicales (CNRTL), Université Nancy-II.