128 PHYSIOGRAPHY. CLASS II. 



parallel to the edges of combination with P and 

 Pr ; Pr + oo streaked horizontally. For the 

 rest as in the preceding species. 

 Lustre vitreous, inclining to resinous, sometimes 

 also a little to pearly upon the perfect faces of 

 cleavage. Colour white prevalent, passing into 

 blueish-grey, sky-blue, and smalt-blue. Also 

 reddish-white and flesh- red. Transparent ... 

 translucent. 



Brittle. Hardness = 3-0. . .3-5. Sp. Gr. = 3-858, 

 a white, translucent, cleavable variety from the 

 Tyrol. 



Compound Varieties. Imperfect globular shapes, 

 surface drusy, composition columnar. Plates, more 

 or less thin : surface rough, composition columnar, 

 thin and parallel. Massive : composition either 

 lamellar, and aggregated into larger granular 

 masses ; or columnar, generally straight and diver- 

 gent ; or granular, the individuals being of vari- 

 ous sizes. Faces of composition smooth, rough, 

 or irregularly streaked. 



OBSERVATIONS. 



1. The subdivisions in the present species are very ana- 

 logous to those effected in the preceding one. Tabular 

 crystals and lamellar compound masses were called Foliated 

 Celestinc, others of columnar crystallisations and composi- 

 tions prismatic Celest'me. Among the massive varieties were 

 distinguished, radiated Celestine, consisting of thin colum- 

 nar compositions, radiating from a centre, fibrous Celestinc, 

 comprehending the thin plates, formed by delicate colum- 

 nar particles of composition, and compart Celestine^ which 



