140 FLINT. 



Very soft, yielding readily to the knife, and 

 easily separable into thin laminae, in 

 which state it is flexible. 



It consists of silver, sulphur, and a little 

 iron. (Wollaston.) 



This rare ore has only been found in 

 Hungary and Saxony. 



The crystal figured by Phillips from the 

 Himmelsfurst mine at Freyberg is, according 

 to Brooke and Miller, a distorted crystal of 

 Silver Glance. 



Brit. Mus., Case 10. 



M. P. G. Wall-case 22. 



Flint. Kirwnn, Phillips. A variety of 

 Quartz somewhat allied to Chalcedony, but 

 more opaque and of dull colours,- which are 

 of various shades of grey, yellow, and black. 

 Translucent, the blackish varieties seldom 

 more than translucent at the edges. Brittle 

 when first extracted, but becomes tougher 

 by exposure. Fracture perfect conchoidal, 

 with sharp cutting edges and a feeble lustre. 

 Slightly harder than common Quartz, which 

 it scratches. It is often coated to a slight 

 depth with a whitish crust, which in some 

 instances appears to be the eff'ect of weather- 

 ing. S.G. 2-59. 



Analysis, by Klaproth : 



Silica 98-0 



Lime 0-50 



Alumina .... 0*25 

 Oxide of iron . . . 0'25 

 Loss ..... 1-00 



100-00 

 BB alone infusible ; but whitens and be- 

 comes opaque when exposed to heat. 



Localities. — British. Flint occurs in the 

 Chalk formation of England, and the north 

 of Ireland, mostly in layers which are pa- 

 rallel with the stratification, and consist of 

 irregularly shaped nodules, or flat tabular 

 bands. The former is the most usual mode of 

 occurrence, and the flints are in general most 

 numerous in the Upper Chalk, where they 

 contain the remains of sponges, alcyonia, 

 echini, and other fossils, sometimes in a sili- 

 cified state, sometimes in the form of casts. 



" We find numerous flints in the Chalk, 

 and indeed in the gravels above it, which, 

 when cut and polished, have a good appear- 

 ance if worked into snuff-boxes and articles 

 of the like kind, particularly when the 

 spongiform bodies included in them are 

 marked by any varieties of colour. In the 

 Greensand the Chalcedony is often extremely 

 beautiful, and pieces sufficiently large to 

 form small cups or vases might be sometimes 

 obtained. Portions of this mineral when 

 worked into seals cannot be distinguished 



FF^OATSTONE. 



from the finest white Camelian, which, in 

 fact, they then are. Both such flints and 

 Chalcedony are found on the coast between 

 Lyme Regis and Sid mouth, where also are 

 discovered some varieties of Jasper (from the 

 Greensand), many species of which closely 

 approach to those known as Egyptian 

 Pebbles, and, indeed, are quite as beau- 

 tiful. Some of the silicified fossil wood is 

 extremely handsome when worked into 

 ornaments.'^ — Report on the Geology of 

 Cornwall, Devon, and W. Somerset, by Sir 

 Henry T. De la Beche, p. 496. 



Flints are also found forming tabular 

 bands and irregular masses in the Purbeck 

 strata, and in Portland Stone: in the former 

 case inclosing remarkably perfect casts of 

 freshwater, and in the latter of marine 

 shells. The lower part of the Portland 

 Stone of Dorsetshire consists in a great 

 degree of Flint. Flint is also found (but 

 rarely) in Scotland, on the shore by Burnt- 

 island, S.W. of Fife. — Foreifin. France. 

 The Danish Islands of Rugen and Zeeland. 

 Spain ; and elsewhere. 



Flint, after having been calcined and 

 ground, is often employed as a substitute for 

 sand in the manufacture of glass, porcelain, 

 and smalt. Formerly it was used in large 

 quantities for making gun-flints; and be- 

 fore the invention of lucifer matches had 

 superseded the old-fashioned tinder-boxes, it 

 was in universal use for obtaining a light, by 

 means of the sparks given off when it was 

 struck against steel ; hence the French name 

 of pierre a feu. In Chalk districts it is 

 employed as a building material, either in 

 its natural rotigh state or squared and 

 dressed, good examples of which latter ap- 

 plication are afforded by houses at Lewes in 

 Sussex, and elsewhere. Flints also furnish 

 an excellent road material; Avhen employed 

 for this purpose they should not be used 

 immediately on being extracted from the 

 qtiarr}^ as they acquire additional toughness 

 by the evaporation of the water contained iu 

 them. 



Brit. Mus., Case 22; 



3I.P. G Horse-shoe Case, ISTos. 703 to 730, 

 736, 739 to 748. Upper Gallerv, Wall-case 

 42, Nos. 1 to 16. 



Flint Coal. A kind of Coal resembling 

 Anthracite. It contains Bitumen, though 

 not to so great an extent as is the case 

 with Carinel Coal. 



Floatstone, Jameson. A variety of 

 Quartz, of a spongy or porous description, 

 Avhich possesses the property of floating in 

 water, until the air contained in its numer- 

 ous cavities is displaced. 



