61 



d- 



these pieces together with haematite ; but the two forms are 

 not intermingled, and no transition between them is found. 



The combination given in the figure 

 consists of: е{^\^} , c?{l40}, s{210}, 

 P{lOl), г^ЗО!}, /"{041 }, w{012}; 

 otherwise the type is somewhat more 

 varying than the two preceding ones, 

 and a few of the forms before mentioned 

 may sometimes be present. The crystals 

 are rather highly compressed from the 

 side ; a characteristic feature is the fact 

 that the prisms Ж{110} and Л{210) 

 are almost always wanting, so that the 

 crystals before and behind are drav^n 

 out into a sharp edge. The form /i{l02}, 

 which we here meet with for the first 

 time, is rather strongly striated, as is 

 also the case with the other faces of these crystals. 



The size of the crystals of this form generally varies be- 

 tween 1 and 2'='°. 



Fig. 8. Ilva i te, type VII. 



Type VIII. 



Of this form only very few crystals 

 are found, all placed on the same piece, 

 surrounded by calcite. 



Combination: ô {OlO} , s{l20}, 

 Л{210}, и{012}, c{00l}, P{lOl}, and 

 £(431}. A few of the forms before 

 mentioned may be found, but are al- 

 ways very inconspicuous. £(43l) has 

 not before been known in ilvaite; it is 

 determined by the following angles : 



Fig. 9. Ilvaite, t.\pe VIII 



