CELESTINE AND BARYTO - CELESTINE OF CLIFTONT. 29/ 



gravity bottle alone and in water. The determination by the first 



method gave 



(i) 4-0205 



(2) 4.0010 



Two determinations in specific gravity bottle — 



(i) 3.912 



(0 3-91^; 



The hardness and angles of the crystals have not yet been 

 ascertained. 



The following description of baryto-celestine is given in 

 ^' Nicol"s Mineralogy," — ^^ radiating, columnar, or foliated, bluish 

 white and friable, H = 2.5 sp. gr. = 3.92, difficultly fusible to a 

 white enamel— 36% SrO, 237o -BaO." 



These numbers calculated into the percentages of sulphates give- 

 Barium Sulphate ... ... 36.2° !o 



Strontium Sulphate ... ... 63.870 



Which compared with the theory 2 SrS04, BaSO^ is — 

 Barium Sulphate ... ... 3 8. 9 



Strontium Sulphate ... ... 61. [ 



And thus the numbers calculated for my specimen agree more 

 closely with the formula 2 BaS04, SrSO^, than the abov-e with 

 2 SrSOj, BaSOi. The mineral described by Nicol appears to 

 agree with mine in most respects, and both must be reckoned as 

 simply mixtures. 



Near the specimen I have just described I found, embedded in 

 the same matrix, but in a different lump, another quantity of what 

 I took to be the same mineral. It was however rather more 

 fibrous, and the crystals were not so well developed. The colour 

 (faint blue) and general appearance were, however, much the same. 

 The analysis of this specimen shows it to have a totally different 

 composition however 5 'the numbers are — 



Barium Sulphate ... ... 7.36 



Strontium Sulphate ... 92.64 



100.00 



