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FLINT (a word See also:common in See also:Teutonic and Scandinavian See also:languages, possibly cognate with the Gr. aXfvOos, a See also:tile); in See also:petrology, a dark See also:grey or dark See also:- BROWN
- BROWN, CHARLES BROCKDEN (1771-181o)
- BROWN, FORD MADOX (1821-1893)
- BROWN, FRANCIS (1849- )
- BROWN, GEORGE (1818-188o)
- BROWN, HENRY KIRKE (1814-1886)
- BROWN, JACOB (1775–1828)
- BROWN, JOHN (1715–1766)
- BROWN, JOHN (1722-1787)
- BROWN, JOHN (1735–1788)
- BROWN, JOHN (1784–1858)
- BROWN, JOHN (1800-1859)
- BROWN, JOHN (1810—1882)
- BROWN, JOHN GEORGE (1831— )
- BROWN, ROBERT (1773-1858)
- BROWN, SAMUEL MORISON (1817—1856)
- BROWN, SIR GEORGE (1790-1865)
- BROWN, SIR JOHN (1816-1896)
- BROWN, SIR WILLIAM, BART
- BROWN, THOMAS (1663-1704)
- BROWN, THOMAS (1778-1820)
- BROWN, THOMAS EDWARD (1830-1897)
- BROWN, WILLIAM LAURENCE (1755–1830)
brown crypto-crystalline substance which has an almost vitreous lustre, and when pure appears structureless to the unaided See also:eye. In the See also:mass it is dark and opaque, but thin plates or the edges of splinters are See also:pale yellow and translucent. Its hardness is greater than that of See also:steel, so that a See also:knife blade leaves a grey metallic streak when See also:drawn across its See also:surface. Its specific gravity is 2.6 or only a little less than that of crystalline See also:quartz. It is brittle, and when hammered readily breaks up into a See also:powder of angular grains. The fracture is perfectly conchoidal, so that blows with a See also:hammer detach flakes which have See also:convex, slightly undulating surfaces. At the point of impact a bulb of percussion, which is a somewhat
elevated conical See also:mark, is produced. This serves to distinguish flints which have been fashioned by human agencies from those which have been split merely by the See also:action of See also:- FROST (a common Teutonic word, cf. Dutch, vorst, Ger. Frost, from the common Teutonic verb meaning " to freeze," Dutch, vriezcn, Ger. frieren; the Indo-European root is seen in Lat. pruina, hoar-frost, cf. prurire, to itch, burn, pruna, burning coal, Sans
- FROST, WILLIAM EDWARD (1810–1877)
frost and the See also:weather. The bulb is See also:evidence of a See also:direct See also:blow, probably intentionally made, and is a point of some importance to archaeologists investigating See also:Palaeolithic implements. With skill and experience a mass of flint can be worked to any See also:simple shape by well directed strokes, and further trimming can be effected with pressure by a pointed See also:- STONE
- STONE (0. Eng. shin; the word is common to Teutonic languages, cf. Ger. Stein, Du. steen, Dan. and Swed. sten; the root is also seen in Gr. aria, pebble)
- STONE, CHARLES POMEROY (1824-1887)
- STONE, EDWARD JAMES (1831-1897)
- STONE, FRANK (1800-1859)
- STONE, GEORGE (1708—1764)
- STONE, LUCY [BLACKWELL] (1818-1893)
- STONE, MARCUS (184o— )
- STONE, NICHOLAS (1586-1647)
stone in a direction slightly across the edge of the weapon. The purest flints have the most perfect conchoidal fracture, and prehistoric See also:man is known to have quarried or See also:mined certain bands of flint which were specially suitable for his purposes.
See also:Silica forms nearly the whole substance of flint; See also:calcite and See also:dolomite may occur in it in small amounts, and See also:analysis has also detected See also:minute quantities of volatile ingredients, organic compounds, &c., to which the dark See also:colour is ascribed by some authorities. These are dispelled by See also:heat and the flint becomes See also:- WHITE
- WHITE, ANDREW DICKSON (1832– )
- WHITE, GILBERT (1720–1793)
- WHITE, HENRY KIRKE (1785-1806)
- WHITE, HUGH LAWSON (1773-1840)
- WHITE, JOSEPH BLANCO (1775-1841)
- WHITE, RICHARD GRANT (1822-1885)
- WHITE, ROBERT (1645-1704)
- WHITE, SIR GEORGE STUART (1835– )
- WHITE, SIR THOMAS (1492-1567)
- WHITE, SIR WILLIAM ARTHUR (1824--1891)
- WHITE, SIR WILLIAM HENRY (1845– )
- WHITE, THOMAS (1628-1698)
- WHITE, THOMAS (c. 1550-1624)
white and duller in lustre. Microscopic sections show that flint is very finely crystal-See also:line and consists of quartz or chalcedonic silica; colloidal or amorphous silica may also be See also:present but cannot See also:form, any considerable See also:part of the See also:rock. Spicules of See also:sponges and fragments of other organisms, such as molluscs, See also:polyzoa, See also:foraminifera and brachiopods, often occur in flint, and may be partly or wholly silicified with retention of their See also:original structure. Nodules of flint when removed from the See also:chalk which encloses them have a white dull rough surface, and ,exposure to the weather produces much the same See also:appearance on broken flints. At first they acquire a See also:bright and very smooth surface, but this is subsequently replaced by a dull crust, resembling white or yellowish See also:porcelain. It has been suggested that this See also:change is due to the removal of the colloidal silica in See also:solution, leaving behind the See also:fibres and grains of more crystalline structure. This See also:process must be a very slow one as, from its chemical See also:composition, flint is a material of See also:great durability. Its great hardness also enables it to resist See also:attrition. Hence on beaches and in See also:rivers, such as those of the See also:south-See also:east of See also:England, flint pebbles exist in vast See also:numbers. Their surfaces often show minute crescentic or rounded cracks which are the edges of small conchoidal fractures produced by the impact of one pebble on another during storms or floods.
Flint occurs primarily as concretions, See also:veins and See also:tabular masses in the white chalk of such localities as the south of England (see CHALK). It is generally nodular, and forms rounded or highly irregular masses which may be several feet in See also:diameter. Although the flint nodules often See also:lie in bands which closely follow the bedding; they were not deposited simultaneously with the chalk; very often the flint bands cut across the beds of the See also:limestone and may See also:traverse them at right angles. Evidently the flint has accumulated along fissures, such as bedding planes, See also:joints and other cracks, after the chalk had to some extent consolidated. The silica was derived from the tests of See also:radiolaria and the spicular skeletons of sponges. It has passed into solution, filtered through the porous See also:matrix, and has been again precipitated when the conditions were suitable. Its formation is consequently the result of " concretionary action." Where the flints lie the chalk must have been dissolved away; we have in fact a See also:kind of metasomatic replacement in which a siliceous rock has slowly replaced a calcareous one. The process has been very See also:gradual and the organisms of the original chalk often have their outlines preserved in the flint. Shells may become completely silicified, or may have their cavities occupied by flint with every detail of the interior of the See also:- SHELL
- SHELL (O. Eng. scell, scyll, cf. Du. sceel, shell, Goth. skalja, tile; the word means originally a thin flake,. cf. Swed. skalja, to peel off; it is allied to " scale " and " skill," from a root meaning to cleave, divide, separate)
shell preserved in the See also:outer surface of the See also:cast. See also:Objects of this kind are See also:familiar to all collectors of fossils in chalk districts.
Chert is a coarser and less perfectly homogeneous substance of the same nature and composition as flint. It is grey, See also:black or brown, and commonly occurs in limestone (e.g. the Carboniferous Limestone) in the same way as flint occurs in chalk. Some cherts contain tests of radiolaria, and correspond fairly closely to the siliceous radiolarian oozes which are gathering at the present See also:day at the bottom of some of the deepest parts of the oceans. Brownish cherts are found in the See also:English See also:Greensand; these often contain remains of sponges.
The See also:principal uses to which flint has been put are the fabrication of weapons in Palaeolithic and See also:Neolithic times. Other materials have been employed where flint was not available, e.g. See also:obsidian, chert, See also:chalcedony, See also:agate and, See also:quartzite, but to prehistoric man (see FLINT IMPLEMENTS below) flint must have been of great value and served many of the uses to which steel is put at the present day. Flint gravels are widely employed for dressing walks and roads, and for rough-cast See also:work in See also:architecture. For road-mending flint, though very hard, is not regarded with favour, as it is brittle and pulverizes readily; binds badly, yielding a surface which breaks up with heavy See also:traffic and in See also:bad weather; and its See also:fine See also:sharp-edged chips do much damage to tires of See also:motors and cycles. Seasoned flintsfrom the See also:land, having been See also:long exposed to the See also:atmosphere, are preferred to flints freshly dug from the chalk pits. Formerly flint and steel were everywhere employed for striking a See also:light; and See also:gun flints were required for See also:fire-arms. A See also:special See also:industry in the shaping of gun flints long existed at See also:Brandon in See also:Suffolk. In 187o about See also:thirty men were employed. Since then the See also:trade has become almost See also:extinct as gun flints are in demand only in semi-See also:savage countries where See also:modern fire-arms are not obtainable. Powdered flint was formerly used in the manufacture of See also:glass, and is still one of the ingredients of many of the finer varieties of pottery. (J. S.
End of Article: FLINT
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