SULPHATE OF POTASH. 159 



STROMN1TE. 



Bary-Strontianite or Stromnite. TRAILL. Trans. Roy. 

 Soc. Edinb. VoL IX. P. 1. p. 81. PHJLL. p. 187- 



Massive : composition thin columnar, and shewing 

 traces of crystallisation. 



Colour yellowish-white internally ; on the outside, 

 where it appears to be disintegrated, it is greyish- 

 white. Lustre inclining to pearly, faint. Trans- 

 lucent. 



Brittle. Hardness = 3-5. Scratches calc-spar, 

 but not fluor-spar. Sp. Gr. = 3-703, TEA ILL. 



According to Dr TRAILL, it contains 



Carbonate of Strontia G8-G. 

 Sulphate of Baryta 27'5. 

 Carbonate of Lime 2-C. 

 Oxide of Iron 0-1. 



It effervesces with acids, but is infusible before the blow- 

 pipe. It occurs in veins along with hexahedral Lead-glance, 

 in a kind of clay-slate at Stromness in Orkney. 



SULPHATE OF POTASH. 

 SALT. 



Potasse sulfate'e. HADY. Traite', 2de Ed. T. II. p. 187. 



Prismatic. P = 131 15', 112 32', 87 34'. VoL I. 

 Fig. 9. AP. 



a : b : c= 1 : V 3'06 i.Jl-69. 



Simple forms. P oo ; P (P) ; P + QD = 106 46' ; 

 (Pr) 3 (a) ; (Pr + <z>) 3 (d) = 67 5^; r (o) 

 = 120 29'; f :Pr + 2=6030'; r + QD (p) ; 

 (Pr + oc) (*). 



