258 INDIUM AND THALLIUM IN 



The crystals give up their water of crystallisation very 

 slowly on heating. The analyses of the salt gave the following 

 result : 



In. 01. H,O 



32-70 49-63 5-30 



Calculated 33-19 51-21 5-20. 



Rb a InCl 5 H a O 



A solution which contains RbCl and InCl 3 in the proportion 

 of two molecules of the first to one molecule of the second 

 deposits on evaporation well-formed crystals of the above 

 composition. This salt is sparingly soluble, and medium-sized 

 crystals can be grown without difficulty. In habit the crystals 

 are more or less tabular on JlOlj, and are usually elongated 

 along the b axis. They show large faces of jlOlj, and fairly 

 well-developed faces of J120J; jOllj and jlOOj are small, but 

 are represented on all the crystals investigated. The general 



Cl,, H,O 

 FIG. 10 



habit is shown in Fig. 10. The reflections are good from all 

 faces except from those of J101J, which frequently give 

 multiple reflections. Dispersion is high. Practically all the 

 crystals are twinned, the twinning plane being JllOj ; the two 

 individuals of the interpenetrating twin cross at an angle of 

 88 22'. The interpenetrating twin, looked at from above, 

 bears a marked resemblance to the iron cross of pyrites, the 

 |120| faces of the second individual appearing through the 

 large faces of JlOlj on the first. 



