45 



(4.0.4.15) : (4.0.4.15) = 



87° 9' 



calculated 



87° 36' 



(2023) :(000I) = 



69° 47' 



calculated 



69° 1' 



(ЮТЗ) :(10Î0) = 



37° 4' 



calculated 



37° 30' 



(lOTo) :(0lT0l = 



59° 55' 





60° 4' 



Calculated 



60° — 



The cordylite crystals are mostly attached by one end to 

 the surface on which they rest; hence, of course only the free 

 end has been capable of crystalline development. Sometimes, 

 however, they are attached by one side (longitudinally); some- 

 times also two individuals have grown together so as to form 

 a cross. In the latter cases both ends are developed. 



The development of these crystals presents a peculiarity 

 of form: they often have a sceptre- or club -like appearance 

 (hence the name of the mineral). This shape is due to the 

 circumstance that the common pyramidal crystal, instead of 

 being , as usual , terminated at both ends by the fundamental 

 pyramid or the base, has got a thinner prismatic prolongation 

 by which the crystal is attached to the surface on which it 

 rests (fig. 9, PI. II). Sometimes there are two such pyramidal 

 crystals grown together by the base (flg. 2, PI. III). ' The re- 

 entrant angle thus formed round the middle of the crystal might 

 be regarded as a mark of twinning. Such a formation is not, 

 however, possible here, if the base, which would be the com- 

 position-face, is a plane of symmetry. Should there be a real 

 twin formation, then the mineral must belong to one of the 

 classes of the hexagonal system in which the base is not a 

 plane of symmetry. There are, however, no other signs indic- 

 ating that this should be the case. The crystals are too small 



