388 



Among the more beautiful of the fossil woods are those which 

 owe their metallization to copper; the finest specimens of which 

 are found in Siberia. The most accurate account of this species of 

 fossil wood is furnished by M. TAbbe Chappe 'd'Auteroche, who 

 travelled, in the year 176*1, into Siberia, where it is found in very 

 considerable quantities, in the copper mines of the Ryphean moun- 

 tains, and in the neighbourhood of Cazan. He describes different 

 kinds of specimens. The first kind he speaks of as copper mine- 

 ralized in sand and wood. In this mine he observes that blend, 

 which he at first took for iron, is distinguishable, mixed with wood, 

 sand, and copper. Those parts which contain the blend and the 

 sandy part, form a very hard and compact stone ; but the vegetable 

 parts which it contains are so friable, as to be very easily detached ; 

 the copper being discoverable in large spots of a beautiful grass- 

 green colour. The wood is black, and resembles charcoal, whose 

 parts are united together by some tenacious matter. The copper is 

 crystallized in many parts of the vegetable substance ; its crystalli- 

 zations forming small cells. These are sometimes of a clear dark 

 or blackish green colour, and possess so much brilliancy, as to give 

 the idea of vitreous crystallizations. The copper is blended through- 

 out with a calcareous earth. The mine from which this mineral 

 was obtained is to the north of Souxson. 



Another mine, to the south of Souxson, he found differed from 

 the one just mentioned only in being more rich, and in the sand 

 and the blend being in a less quantity. In this mine were many 

 parts of an azure blue, sometimes in layers, and frequently in 

 patches. Speaking of copper mineralized in wood, he says, It may 

 be discovered, by the specimen which I brought, that it belonged 

 to a tree which was at least a foot in diameter. The internal part 

 is reduced almost to charcoal, being very friable, although the parts 

 are held together by a tenacious matter. The copper is sometimes 

 crystallized in little cells, resembling those of an honey-comb ; but 



