ORDER I. PRISMATIC GYPSUM-HALOIDE. 65 



these properties to the preceding species, which generally 

 occurs along with it, particularly in small crystals lining 

 the fissures which traverse the mass in all directions. Cleav- 

 age yet enables us to distinguish this decomposed substance, 

 which has been called Chaux sulfatie epigene by HAUY, from 

 the real and determinable varieties of prismatoidal Gyp- 

 sum-haloide. The change is here exactly the reverse of 

 what happens in the decomposition of hemi-prismatic Na- 

 tron-salt, and of prismatic Glauber-salt, &c., which lose 

 their water, instead of attracting a portion of it, like the 

 prismatic Gypsum-haloide. 



3. The repositories of the preceding species are in general 

 at the same time those of the present one, by which it is 

 commonly accompanied : yet it does not form beds by it- 

 self. It is also found along with metallic minerals, as at 

 Bleiberg in Carinthia, with hexahedral Lead-glance, and 

 occurs in globular masses of various sizes in the beds ojf 

 clay, which accompany prismatoidal Gypsum-haloide and 

 hexahedral Rock-salt. 



4. Splendid geodes of large and well defined crystals 

 (Fig. 26.) of this species have been found at Aussee in 

 Stiria, other crystallised varieties at Hall in the Tyrol, at 

 Hallein in Salzburg, in Switzerland, &c. ; accompanied by 

 large grained cleavable masses. The blue Anhydrite is 

 found at Sulz on the Neckar, and at Bleiberg in Carin- 

 thia. Columnar varieties occur at Ischel and Berchtesga- 

 den ; compact ones, besides these localities, also in the 

 Hartz, in Mansfeld, &c. ; the contorted varieties are 

 found at Wieliczka and Bochnia in Poland. The decom- 

 posed prismatic Gypsum-haloide occurs in considerable 

 masses at Aussee in Stiria, at Bex in Switzerland, and 

 other places. 



5. The blue varieties, in which the granular particles of 

 composition cohere more firmly than in others, are cut 

 and polished for various ornamental purposes, as also in 

 Italy the Vulpinite, which has been called Marino bar, 

 digtto di Bergamo. 



VOL. II. E 



