170 



TRAVELS IN BRAZIL. 



must be considered as such a one, and, consequently, not 

 essentially differing from the usual formation of the mica- 

 slate. 



Notwithstanding all that has been said, for some years 

 past, respecting the occurrence of topazes in Brazil, there 

 always has remained, on nearer examination, great uncer- 

 tainty and doubt. Mr. Von Eschwege, in Baron Von 

 MolPs Annals, vol.iii. No. 3., says — "Chlorite-slates are ge- 

 nerally the lower ranges of the higher sandstone mountains, 

 and in them they dig for topazes in the country round Villa 

 Rica ; topazes are found in them only irregularly, here and 

 there in nests and kidneys of lithomarge, fine white sand, rock- 

 crystal, all which lie loose and promiscuously aggregated, 

 partly crystallised, partly in irregular sharp-edged pieces ; 



sometimes the topazes are imbedded in rock-crystal 



The manner in which the topazes are obtained is with broad 

 hoes, as the chlorite-slate is quite decomposed and forms ful- 

 lers'-earth, &c." In the Journal of Brazil, the same gentle- 

 man remarks: — " The Morro Deos te Livre consists of 

 sand-stone and chlorite-slate. ..... From this place to Capao 



de Cane, the principal species of rock is clay-slate, here and 

 there forming a passage into chlorite-slate. This latter 

 forms smaller mountains, often much decomposed and fer- 

 ruginous, passes into fullers'-earth, and is then the matrix 

 of the yellow topazes, which are frequently found in it in 

 nests, with lithomarge. The chief mine is at Capao. All 

 the topazes found there have the peculiarity that they are 

 broken ; not a single crystal is found growing to another 

 rock ; even the rock-crystal, which occurs with them, is also 

 broken ; sometimes it is seen growing together with a topaz. 

 The topazes, as well as the rock-crystal, show, in the frac- 

 ture, a great freshness, as if they were but just broken, and 

 lie in nests confusedly mixed together, surrounded with 

 lithomarge. It is extremely difficult to form a hypothesis 

 in what manner they came into the regularly stratified 



