103 



needle-shaped individuals, elpidite in while columns often 

 in parallel, sometimes in radiated groups, and black pseudo- 

 morphous rhombohedra of rh od о chr о site. 



20. Zircon. 



In the Greenland syenites the occurrence of zircon as a 

 macroscopic mineral is probably rather rare. Only in the 

 small islands of Kitsigsut off the coast between Sanerut and 

 Nunarsuit it occurs, according to the statement ofGieseckeM 

 in a quantity worth mentioning. In the sodalite-syenite on the 

 firths of Kangerdluarsuk and ïunugdliarfik zircon has only been 

 found as a microscopical alteration product of eudialyte ^). In 

 the Ltitzen collection only a single zircon crystal has been 

 found ^). As, however, this crystal did not resemble any one of 

 those which I have afterwards found on Narsarsuk, it probably 

 was derived from some other locality. 



The zircon individuals found on Narsarsuk are with regard 

 to their crystallographic development of two distinct and well- 

 marked types, which are described below. 



Type I. 



To this type we refer crystals of the very common develop- 

 ment represented by Fig. 1 , Plate VI. The largest individuals 

 that have been met with measure about 2*=™ in length by nearly 

 the same thickness. No other forms than those figured have 

 been observed. They are 



m = {по}, p = {ill}, и = {33l}. 



The prism of the first order m and the fundamental pyra- 

 mid, p, are the predominant forms. The faces belonging to the 



^) Giesecke's Mineralogiske Reise i Grønland, Copenhagen, 1878. 



2) This Journal, Vol. 14, 1894, p. 172. 



3) Zeitschr. f. Kryst., Vol. 23, 1894, p. 366. 



