

1819.] the Turquoise and the Calaite. 419 



6. Dens Mola rt's of an Animal of the Stag Genus. — (See fig. 6.) 

 This tooth was found in a copper mine in the government of 



Olonez, which has been abandoned these 20 years. I am 

 indebted for it to the kindness of M. de Foullon, who possesses, 

 perhaps, the most instructive collection of these interesting 

 countries. 



7. Dens Molaris of a carnivorous Animal. — (See figs. 3 and 4.) 

 This tooth has lost one of its roots. The eminences of the 



summit are partly obliterated. It is entirely covered with a ver- 

 digris-coloured oxide of copper. 



The place where it was found is unknown. It is very probable 

 that we shall hereafter discover several other teeth equally 

 entitled to the name of turquoise. And from what I have said 

 in answer to the first question, other parts may be susceptible of 

 the same change. 



Answer to the third Question, Where do the principal Depots 



occur? 



The principal depots which have served to form turquoises are 

 those of France. They occur in Lower Languedoc, near the 

 town of Simore and its environs, as at BaillaOatz and at Lay- 

 mont. There are others, according, to Reaumur, nearly in the 

 same country, on the side of Audi, at Gimont, and at Castres. 



Guy la Brosse, in his work (of 1628, p. 421), On the Nature 

 and Utility of Plants, is the first person that makes mention of 

 it. He calls Licome minerale and mother of the turquoises 

 (p. 467 and 521). " The licome," says he, " is a stone having 

 the shape of a horn, and the consistence of a stone, which, 

 being exposed to a graduated heat, gives the true turquoise. It 

 is called licome minerale because it resembles the horn of an 

 animal. 



We learn two things from this notice of Guy la Brosse : 



1 . That tusks were employed for forming good turquoises ; 



2. That the true colour is given by the fire. 



Reaumur described afterwards the manner of heating the 

 turquoise, and gives a figure of the peculiar furnace employed 

 for the purpose. From this, what I stated above follows clearly ; 

 that the French turquoises are prepared by the fire, and conse- 

 quently are partly artificial. 



Other depots are likewise mentioned, from which I have not 

 yet seen specimens ; namely, Nivemois, Silesia, Lesta in Bohe- 

 mia, Thurgau in Switzerland. We must add likewise from my 

 observations, Siberia (Miask), and the government of Olonez. 

 The number of places will doubtless augment in proportion as 

 more attention is paid to fossils. 



I shall finish this dissertation with the question, how can we 

 distinguish a turquoise from a calaite, or the turquoise of France 

 from the turquoise of Persia ? The hardness is the first character. 

 Dibtilled vinegar deprives it of its colour, and nitric acid dissolves 



2 i>2 



