INFRA-RED REFLECTION SPECTRA. 



BARITE (BaSO). 

 (Massive. Curve b, fig. 60.) 



The reflection decreases normally from 4 to 6.8 p., then abnormally to 

 7.8 p.. There are maxima at 8.35, 8.9, and 9.1 ft, followed by a trans- 

 parent region to 12 p., where the present observations cease. The reflec- 

 tion appears to increase at 11.5 p.. 



30 



o 



+3 

 u 



cr 



/o 



6789 

 FIG. 61. Celestite (a); Kieserite. 



10 



U 



CELESTITE (SrSCu). 

 (Cleavage parallel to c. Curve a, fig. 61.) 



The reflection curve is similar to the preceding, with maxima at 8.2, 

 8.76, and 9.1 p.. The region beyond g p. is evidently complex, with a 

 possible maximum at 9.3 p.. 



* 



KIESERITE (MgSO4+2H 2 O). 

 (Massive. Curve b, fig. 61.) 



This mineral is hydroscopic, and does not take a high polish. The 

 two small maxima occur at 8.7 and 9.25 p., respectively. 



FIG. 62. Glauberite (a) \ Ferrous sulphate. 



GLAUBERITE (NaSCXCaSO*). 

 (Ground parallel to c. Curve a, fig. 62.) 



^i 



The maxima in this curve are not well denned, particularly the one 

 at 9.1 p. and the one at 8.3 p.. The band at 8.7 p, is not so sharp as in 

 selenite. 



