558 SYSTEMATIC DESCRIPTION OF PRECIOUS STONES 



Sainte-Colombe, Dourban, Segure, Payrat, Bastide, and others. At that time about 1000 

 hundredweights of jet of local and foreign origin was annually worked up. The finished 

 articles were exported in large quantities to Spain, 180,000 francs' worth of goods being 

 received by that country annually, also to Italy, Germany, Turkey, and other parts of the 

 Orient. With the fall of jet ornaments into disfavour came the decay of the industry, and 

 in 1821 the net gain from the rough material and finished articles amounted only to 

 35,000 fi-ancs, while at the present day the industry is practically dead. 



In Wurtemberg jet is found, under the same conditions as at Whitby, in the 

 Posidonia beds of the Upper Lias ; for example, at Schiimberg, Balingen, Boll, and many 

 other places in the Swabian Alps. Abundance of jet is here easily obtained, and efforts 

 have been made to establish an industry to rival that of Whitby. These attempts have 

 received liberal Government support, but in spite of this, the workshops established at 

 Gmiind, Balingen, and other places have been obliged to close, being unable to compete 

 successfully with Whitby. 



In North America material equal in quality to AVhitby jet is found in the southern 

 part of Colorado, in Wet Mountain Valley, and especially in El Paso County. It is very 

 little used, however, for the manufacture of ornaments, and this is also the case with the 

 fine material found at Pictou, in Pictou County, Nova Scotia. On the other hand, a black 

 coal with a somewhat metallic lustre, known as anthracite, is sometimes used in the same 

 way as is jet, especially that from Peimsylvania. In America the use of jet for mourning 

 ornaments is largely replaced by " black onyx," that is to say, by an artificially coloured onyx 

 or agate, which is of a deeper black, brighter, harder, and more dui'able than jet, and which 

 can be obtained from Oberstein very cheaply. At present there has been no attempt to 

 establish a jet industry in the United States, in spite of the occurrence of abundance of 

 rough material of suitable quality. 



Jet furnishes a material for the manufacture of moiu'ning ornaments of all kinds, 

 including brooches, bracelets, necklaces, cross-shaped pendants, &c. It is also used for such 

 articles as rosaries, snuff-boxes, ink-stands, candlesticks, and stick-handles. These objects 

 are usually first roughly fashioned with a knife or file, and then finished on the lathe or 

 grinding lap. They may be more or less artistically carved ; and, finally, are polished, this 

 operation being performed with the palm of the hand. 



Jet articles, even of the best quality, are worth but little, the only exceptions being in 

 the case of objects of special artistic design and workmanship. Notwithstanding the 

 cheapness of the genuine material, it is not uncommon to see mourning ornaments and 

 other articles, purporting to be of jet, made in reality of some other black substance. A 

 material which frequently replaces the use of jet is glass, either natural (obsidian) or 

 artificial. It is never difficult, however, to decide whether one is dealing with jet or glass, 

 for the latter is harder, heavier, and much more brilliant than the former, and, moreover, 

 feels cold to the touch, while jet feels warm. Other substances used in place of jet are 

 black onyx, black tourmaline, and black garnet (melanite), each of which diffbrs from jet in 

 the same ways as glass. An artificial product of much the same chemical composition as 

 jet is vulcanite. These substances are very similar in appearance, and both feel warm to 

 the touch; but vulcanite, even when lightly rubbed with a cloth, becomes strongly 

 electrified, and readily attracts bits of paper, while jet does not. Vulcanite in a plastic 

 condition can be pressed into a mould, and articles made of it are therefore often decorated 

 in bas-relief. The blunt contours of such figures, however, make it at once clear to the 

 expert that he is dealing not with figures carved in jet, which are remarkable for sharpness 

 of outline, but with the impression of a mould. 



