214 



DESCRIPTIVE MINERALOGY. 



to pearly. In tliin plates, translucent. Brittle, and easily frangible. Hardness 3.5. Specific 

 gravity from 3 . 70 to 3 . 90. Infusible before the blowpipe. Partly soluble, with effervesence, 

 in nitric and muriatic acids. 



Composition. Specimen from Stromness, in one of the Orknejj islands. Carbonate of 

 strontia 68.60, sulphate of baryta 27.50, carbonate of lime 2.60, oxide of iron 0.10 [Trail). 



Although I have introduced the above description of this mineral, it is by no means certain 

 that it is entitled to the rank of a distinct species. The only fact in favour of the latter view 

 is, that according to the above analysis, the carbonate of strontia is in the ratio of four atoms 

 to one atom of sulphate of baryta. This, however, may be accidental. 



LOCALITIES. 



Oneida County. A mineral was many years since found near Hamilton College, which 

 agrees very well with the above description ; and Dr. Emmons supposes the same mineral to 

 occur in Schoharie county. 



ORDER III. LIME. 



This order embraces the following species : 



CARBONATE OF LIME. 



A mineral yielding caustic or quicklime by calcination; soluble with effervescence in dilute 

 nitric or muriatic acids : the solution affording an abundant precipitate with oxalate of ammo- 

 nia. 



There are several important sub-species or varieties, which it will be convenient and proper 

 to notice separately. 



