/О 



The single more common feature is the tolerably common 

 occurrence of haematite, more rarely pyrite or magnetite, together 

 with the ilvaite or at all events in its immediate vicinity. 



An examination of the axial ratios in the ilvaite from the 

 different localities gives similar, characteristic differences; the 

 two Greenland localities are also in this respect very nearly 

 related, but occupy a position between the other forms. As 

 these facts are closely connected with the chemical composition, 

 especially with the percentage of MnO, they will be treated 

 more particularly hereafter. 



All the forms found in the ilvaite from Siorarsuit, are the 

 following, arranged as far as possible according to their fre- 

 quency and size ; those marked * have not before been found 

 in ilvaite. 



1. In all or almost all types: b[o\0}, s{l20}, /г{210), P{lOl}. 



2. In the majority of types: 



a. sometimes reaching to a rather considerable size: i6'(30l}, 

 /•{041}*, o{l\\}. 



b. always rather insignificant: e{02l}, if{ll0}. 



3. Rather common forms: 



a. often very predominant: c{43l}*, ^■{41i}, c{00l}, '>^{012}. 



b. rather insignificant: 6/{l40}, /{l2l}, (t{081}*. 



4. More rare forms only found in a single or a few types : 



a. sometimes rather conspicuous: w(l3l}, ж{211}, C{33l)*, 

 у {311}. 



b. very insignificant: ш{б21}*, /{l30}, j'{l60}*, ^^{Oll}, 

 «y{63l}*, j{40l}*, v{340}. 



The most important of the angles calculated for the above 

 mentioned faces, are the following: 



а:Ъ:с = 0,б7бб : 1 : 0,4499. 

 ^:è = (160):(010) = 13°50' y :è = (340):(010) = 47°57' 



(^:è = (140):(010) = 20°16V4' Ж :ô = (1 10) :(010) = 55°55' 

 t'.b = (130):(010l = 26°i3V''2' Л :5 = (210): (010) = 71°18V2' 

 s:J = (120):(OIO) = 36°28' *P: с = (101) :(001) = 33°37VV 



