382 GNEISS 



Javita, San Carlos del Eio Negro, and the Peak of Duida, 

 the granite is traversed by numerous veins of different ages, 

 abounding with rock-crystal, black tourmalin, and pyrites. 

 It appears that these open veins become more common on 

 the east of the Peak of Duida, in the Sierra Pacaraina, 

 especially between Xurumu and Bupunuri (tributaries of 

 the Bio Branco and the Essequibo), where Hortsmann dis- 

 covered, instead of diamonds* and emeralds, a mine (four) 

 of rock-crystal. 



(5) GNEISS predominates along the littoral Cordillera of 

 Venezuela, with the appearance of an independent forma- 

 tion, in the northern chain from Cerro del Chuao, and the 

 meridian of Choroni, as far as Cape Codera; and in the 

 southern chain, from the meridian of Guigne to the mouth 

 of the Bio Tuy. Cape Codera, the great mass of the Silla 

 of Galipano, and the land between Guayra and Caracas, the 

 table-land of Buenavista, the islands of the lake of Valencia, 

 the mountains between Guigne, Maria Magdalena, and the 

 Cerro de Chacao, are composed of gneiss ;f yet amidst this 

 soil of gneiss, inclosed mica-slate re-appears, often talcous 

 in the Valle de Caurimare, and in the ancient Provincia de 

 Los Mariches ; at Cabo Blanco, west of La Guayra ; near 

 Caracas and Antimano, and above all, between the table- 

 land of Buenavista and the valleys of Aragua, in the Mon- 

 tana de las Cocuyzas, and at Hacienda del Tuy. Between 



* These legends of diamonds are very ancient on the coast of Paria. 

 Petrus Martyr relates, that at the beginning of the sixteenth century, a 

 Spaniard named Andres Morales bought of a young Indian of the coast 

 of Paria " admantem mire pretiosum, duos infantisdigitiarticuloslongum, 

 magni autem pollicis articulum sequantem crassitudine, acutum utrobique 

 et costis octo pulchre formatis constantem." [A diamond of marvellous 

 value, as long as two joints of an infant's finger, and as thick as one of the 

 joints of its thumb, sharp on both sides, and of a beautiful octagonal 

 shape.] This pretended " adamas juvenis pariensis " resisted the action of 

 lime. Petrus Martyr distinguishes it from topaz by adding, "offende- 

 runt et topazios in littore," [they pay no heed to topazes on the coast] that 

 is of Paria, Saint Marta, and Veragua. See Oceanica, Dec. iii, lib. iv. 

 p. 53. 



t I have been assured that the islands Orchila and Los Frailes are also 

 composed of gneiss ; Curacao and Bonaire are calcareous. Is the island 

 of Oruba (in which nuggets of native gold of ronsiderabie sue have 

 been found) primitive ? 



