882 
GKEISS STRATA. 
Javita, San Carlos del Eio Negro, and tlie Peal? 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 tlie Peak of Duida, in the Sierra Pacaraina, 
especially between Xurumu and Eupunuri (tributaries of 
the Eio Branco and the Esseqiiibo), where Hortsmann dis- 
covered, instead of diamonds'* and emeralds, a mine (four) 
of rock-crystal. 
(J) 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 Eio Tuy. Cape Codera, the great mass of the SiUa 
of Galipano, and the land betw'een 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 gieiss ;t yet amidst this 
soil of gneiss, inclosed mica-slate re-appears, often talcons 
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 infantis digit! articulos longutn, 
magni autem pollicis articulum mquantem crassitudiue, acutum utrobique 
et costis octo pulchro formatis constantem.” [A diamond of marvellous 
value, as long as two joints of an infant‘8 huger, 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 topax by adding, ^‘offende- 
runt et topazioa 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. 
+ I have been assured that the islands Orchila and Los Frailes are also 
composed of gneiss; Curavao and Bonaire are calcareous. Is the island 
of Oruba (in which nuggets of native gold of considerable size have 
been found) primitive ? 
