188 



TRAVELS IN BRAZIL. 



tity of white quartz, it appears grainy and striped. 

 These thin strata alternate sometimes with others 

 of decomposed and crumbly quartz. The stone 

 often contains so much iron, that it may be smelted 

 to advantage. * A considerable quantity of gold 

 is disseminated throughout this mica-slate, and in 

 particular abundance in the quartz veins which 

 traverse it. At the base of the mountain, and 

 about four to five hundred feet up it, there are, in 

 several places, layers of mica (Von Eschwege's 

 talc and chlorite-slate), in large tables, sometimes 

 of an even, sometimes of a conchoidal fracture, 

 which are perfectly similar to those that occur at 

 Capao and Lana. No gold has been observed in 

 them. This kind of mica-slate is not everywhere 

 uniformly incumbent on the Morro, and in many 

 places it is entirely wanting, and then that kind of 

 mica-slate immediately appears, which constitutes 

 the greater part of the mountain, namely, the 

 quartzy, granular mica-slate, or what is called 

 elastic quartz, which we are inclined to designate 

 by the name of quartz-slate, t The texture of 

 this kind of rock is most evidently slaty on the 

 whole Morro, and where the upper layers of the 



* This is the case, for instance, in the iron-foundry of An- 

 tonio Pereira on the Serra de Carassa, and near Gaspar Soares. 

 There are, besides, in many places in Minas large strata of a 

 mica-slate, which, by the iron-coloured mica which it contains, 

 and by a similar structure, greatly resembles the mica-slate 

 containing specular iron-ore. 



f See Note 5. page 202. 



