17 



The crystals of fluorite are generally small in size , litHe 

 more than '/'i*^"" in diameter. They are bluish-grey, sometimes 

 pale green in colour and in the fresh state presenting sharp edges 

 and corners, and plane and brilliant faces. The predominant 

 form is the rhombic dodecahedron, which is often the only one 

 present. Cubic faces are subordinate , and still more rarely 

 octahedral faces. Well-developed crystals have been found 

 especially at the localities Nos. 2 and 8. In the crystal 

 druses the fluorite individuals always are the outermost, which 

 indicates that they are the last formed. On specimens that 

 have been long exposed, the crystals are more or less rounded 

 by atmospheric action. Also the massive fluorite under the 

 same conditions is in a state of much advanced decomposition. 

 One can see how the decomposition has proceeded along the 

 cleavages. 



5. Quartz. 



That the mineral occurrences in the syenite of South Green- 

 land present important analogies with those of Langesund in 

 Norway, is a fact which has frequently been pointed out. This 

 agreement has chiefly or rather exclusively been staled with 

 reference to the sodalite-syenite district between atid about the 

 Firths of Kangerdluarsuk and Tunugdliarfik, as it is chiefly this 

 district that has hitherto been investigated. Now the fact is, that 

 this Greenlandian syenite district consists, like the Norwegian 

 locality, of basic rocks with no trace of quartz. The great 

 syenite area about Igdlerfigsalik , on the other hand, has till 

 now been almost unknown, and is, as far as regards its 

 petrography, still so. It will, however, probably prove to be 

 of a different character from that of the neighbouring sodalite- 

 syenite district. This is at least indicated by the mineral 

 occurrences on the plateau of Narsarsuk, which, in contra- 

 distinction to the above-mentioned, are fairly rich in quartz. 

 XXIV. 2 



