S66 Count de Bournon o« Bat'digUone. 



Compact Bard/glionc. 



This variety Is less compact In Its texture than compact carbonate 

 of Hme, or compact feldspar : Its substance, at least in all the speci- 

 mens which I have hitherto had an opportunity of observing, being 

 more or less mixed v^^Ith small particles of lamellar bardiglione* 

 Hence Its fracture Is very rough and irregular ; but we can always 

 distinguish in it those little prominent and somewhat detached splin- 

 ters, which are characteristic of minerals having a compact structure. 

 This variety has generally a slight semitransparency at its edges. 



1. Mixed ivith quartz. This variety of the compact bardiglione 

 occurs with the lamellar variety at Vulpino ; the quartz which it 

 contains is sometimes visible with a good lens. 



2. Mixed ivith sea-salt. The salt-rock of Arbonne belongs to this 

 variety. Hitherto this rock has been considered as a gypsum mixed 

 with sea-salt ; but all the specimens I have yet seen, and which have 

 been sent to me by my friend Gillet de Laumont, belong no 

 doubt to the species bardiglione. This variety includes also in its 

 substance very brilliant small laminas of bardiglione, and its fracture 

 is more irregular than that of the pure compact variety. 



The salt-rock of Arbonne presents two varieties of this substance ; 

 one of a dirty grey, and the other a little reddish. The latter of 

 these varieties is somewhat closer and finer grained than the other, 

 and it is also less loaded vvdth sea-salt. Very small dodecahedral 

 crystals with pentagonal faces of Iron pyrites, are disseminated 

 through its substance. Sm.all globules of compact bardiglione, very 

 easily separable from the substance inclosing them, are likev^'ise in- 

 cluded in it. These litde globules are destitute of the brilliant 

 laminse observable in the surrounding mass, are of a brown colour, 



