PHYSIOGRAPHY. 119 



Celestine. 



Lustre vitreous, inclining to resinous ; sometimes also, a 

 little to pearly on the perfect faces of cleavage. Color 

 white prevalent, passing into bluish-grey, sky-blue and 

 smalt-blue. Also reddish-white and flesh-red. Transpa- 

 rent . . . translucent. 



Brittle. Hardness = 3*0 ... 3-5. Sp. gr. = 3-858, a 

 white translucent, cleavable variety, from the Tyrol. 



Compound Varieties. Imperfect globular shapes, sur- 

 face drusy, composition columnar. Plates more or less 

 thin : surface rough, composition columnar, thin and par- 

 allel. Massive : composition either lamellar and aggrega- 

 ted into larger granular masses ; or columnar, generally 

 straight and divergent ; or granular, the individuals being of 

 various sizes. Faces of composition smooth, rough or ir- 

 regularly streaked. 



1. The varieties of the present species have been variously divided in 

 the mineralogical systems into subspecies and kinds, notwithstanding they 

 are connected among themselves by immediate transitions. Tabular 

 crystals, and lamellar compound masses, were called foliated Celestine; 

 others of columnar crystallizations and compositions, prismatic Celestine. 

 Among the massive varieties were distinguished radiated Celestine, con- 

 sisting of thin columnar compositions, radiating from a centre ; fibrous 

 Celestine, comprehending the thin plates, formed by delicate columnar 

 particles of composition; and compact Celestine, which is a mechanical 

 mixture of Celestine and Calcareous Spar. 



Before the blow-pipe, Celestine decrepitates and melts, without per- 

 ceptibly coloring the flame, into a white friable enamel. It loses its 

 transparency on being heated, and acquires a caustic taste different from 

 that of Heavy Spar under similar circumstances. Reduced to powder, 

 it phosphoresces upon red hot iron. 



2. Jlnalysis. 

 By KLAPROTH. 



Strontia .... 56-00 



Sulphuric acid . . . . 44 00 



