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fers only by containing neither quartz, nor 

 garnets, nor pyrites. The intimate relations., 

 that we observed near the Cerro de Chacao, 

 between the gruenstein and the serpentine, 

 cannot surprise these geognosts, who have 

 studied the mountains of Franconia and Silesia. 

 Near Zobtenberg *, a serpentine rock alternates 

 also with gabbro. In the country of Glatz, the 

 fissures of the gabbro are filled with a steatite of a 

 greenish white colour ; and the rock, which was 

 long thought to belong to the gruensteins -f-, is an 

 intimate mixture of feld-spar and diallage. 



The gruensteins of Tucutunemo, which we 

 consider as constituting the same formation 

 with the serpentine rock, contain veins of mala- 



* Between Tampadel and Silsterwiz (Bucb, Geogn. Beob. 

 vol. i, p. 69 ; and Naturf. Freunde zu Berlin, 1810, vol. iv, 

 144). 



f Leop. de Buck, Descr. de Landeck, translated by Mr. 

 d'Aubuisson, p. 26. In the mountains of Bareith, in Fran- 

 conia, so abundant in gruenstein and serpentine, these two for- 

 mations are not connected together. The serpentine there 

 belongs rather to the schistoid hornblende {hornhlendschiefer), 

 as in the island of Cuba. Near Guanaxuato, in Mexico, I saw 

 it alternating with syenite. These phenomena of serpentine 

 rocks forming layers in eurite (weisstein), in schistoid horn- 

 blende, in gabbro, and in syenite, are so much the more re- 

 markable, as the great mass of garnetiferous serpentines, 

 which are found in the mountains of gneiss and mica-slate, 

 form little distinct mounts, masses not covered by other for- 

 mations. It is not the same in the mixtures of serpentine 

 and granulous limestone. 



