418 



the inelosures of the gardens of Caraecas, erect- 

 ed partly with fragments of gneiss, we find gar- 

 nets of a very fine red, a little transparent, 

 and very difficult to detach. The gneiss near 

 the Cross of La Guayra, half a league distant 

 from Caraccas, presented me also vestiges of 

 azure copper ore * disseminated in veins of 

 quartz, and small strata of graphite, or earthy 

 carburetted iron. This last, which leaves traces 

 upon paper, is found in pretty large masses, 

 and sometimes mingled with sparry iron ore, 

 in the ravin of Tocume, to the west of the 

 Silla. 



Between the spring of Sanchorquiz and the 

 Cross of La Guayra, as well as still higher up, 

 the gneiss contains considerable beds of sac- 

 charoidal bluish-gray primitive limestone, coarse 

 grained, containing mica, and traversed by 

 veins of white calcareous spar. The mica with 

 large folia, lies in the direction of the dip of 

 the strata. I found in the primitive limestone 

 a great many crystallized pyrites, and rhom- 

 boidal fragments of sparry iron ore of Isabella 

 yellow. All the pains I took to find some tre- 

 molite-f*, which in the Fitchelberg, in Franco- 



* Blue carbonated copper. 



t Grammatite of Mr. Hatiy. The primitive limestone 

 above the spring at Sanchorquiz is directed, as the gneiss in 

 that place, hor. 5*2, and dips 45° north; but the general 

 direction of the gneiss is, in the Cerro de Avila, hor. 3*4, 



