130 



An ore of tita- 

 nium, 



and of magne- 

 tic iton. 



Chrysolites. 



Mica. 



Asbestus. 



Amianthoid. 



Chlorite. 



Cd class. 

 Sulphur. 



MINERALOGY OF CHALANCHES. 



of the most beautiful varieties of syenite granitello. TwO 

 associations peculiar to the amphibole of Chalancbes are, 

 1, a calcareo-siliceous titanite in crystals of a lemon yellow, 

 which form a pleasing contrast with the dark green of the 

 amphibole in laminar masses : 2, a magnetic oxidule of iron 

 in indeterminate crystals of a black metallic brown with a 

 laminar fracture. 



Some veins of arseniated cobalt ore very rich in silver, 

 and even frequently presenting this metal in its native state, 

 contain a mixture of small greenish crystals, which might 

 be taken at first sight for granulous epidote, but appear to 

 me to be peridot. I could not observe any distinct figure 

 in them : they are disseminated in small irregular grains 

 amid arseniated or oxided cobalt ; frequently they are with 

 sulphuretted silver; and sometimes they are covered with 

 native silver. This mixture is one of the least common at 

 Chalanches, but it is one of the most remarkable for the 

 variety of its constituent substances, and its richness in sil- 

 ver amounts to 18 or 20 hect. of metal in a myriagr. of ore 

 [18 or 20 per cent]. 



Mica is very abundant in the rocks of Chalanches. It is 

 in hexaedral laminae frequently very well defined ; and in 

 colour white, yellow, gray, or blackish. The celebrity of 

 the mines of Chalanches, and the appearance of the great 

 quantity of silvery white mica in its cliffs and declivities, 

 have led many persons but little versed in mineralogy to 

 suppose, that the whole mountain was formed of silver. 



Asbestus is very common in the veins at Chalanches. It 

 is found in different states, and modified by various mixtures. 

 Frequently it is very rich in silver, and thrown into the fur- 

 nace with the ore. 



The amianthoid of Chalanches is in fine, slender, silky 

 needles, sometimes stiff and elastic, of a silky green co- 

 lour. It is frequently tinged by oxide of iron, or of man- 

 ganese. 



Chlorite talc is very abundant in the veins, both in com- 

 pact masses and pulverulent; and in each state it frequently 

 contains native silver. 



In the third class, combustible substances not metallic, 

 there are only sulphur and anthracite. Sulphur is very 



common 



