80 DOMAIN iX. ANOMALOUS. 



position is found at Serviere, above Brian9on; 

 but the diallage, or smaragdite, is black, yellow, 

 bronze, grey, or silver-grey*. In other in- 

 stances, the diallage has a metallic splendour; 

 and the author has a specimen, which he re- 

 ceived from Faujas, of a rock composed of ser- 

 pentine and felspar, containing metallic diallage; 

 and which was discovered by the Marquis de 

 Cubieres, in the ruins of Pompeia ; so that 

 scarcely a beautiful rock can be said to have 

 escaped the researches of the ancients : and the 

 ruins of Rome are found to present about two 

 hundred and fifty kinds, while those of London 

 would only afford white marble. 



The most complete account of the beautiful 

 rock here called Corsilite, may be found in Pa- 

 trin's ingenious system of mineralogy. The 

 Smaragdite. smaragdite, he observes, was formerly called 

 mother of emerald; and sometimes appears to 

 have passed even for emerald itself. This sub- 

 stance is a singular combination of many con- 

 stituents, as may be judged by the following 

 analysis, by Vauquelin, of the green and grey 

 smaragdite ; a name which might be retained as 

 a compliment to its great observer, and as the 

 green is its most usual and beautiful colour. 



* Brard, ii. 30Q. 



