144 
llimausak complex amounts to 20 km? or a little less. These 
figures, however, are only to be regarded as approximate. 
The general shape of the naujaite-body is that of a toler- 
ably flat or slightly concave sheet. In the higher parts of the 
mountains it is overlain by the sodalite-foyaite. It rests upon 
lujavrite. Between the naujaite and the sodalite-foyaite there is 
always a gradual transition; towards the lujavrite the contact as 
a rule is well marked though transitional forms are found in 
some places. 
Colour. — The colour of the naujaite cliffs when seen at 
some distance is light gray; upon closer inspection or in hand 
specimens the rock has a conspicuously motley appearance 
owing to the large dimensions of the individual white, greenish, 
red, and black crystals and anhedra. On freshly broken sur- 
faces the sodalite exhibits a magnificent, deep bluish-red colour 
which rapidly disappears when the surface is exposed to the 
light (p. 33) 
Mineralogical characters. — The main constituents are 
sodalite, nepheline, alkali-felspar, egirine, arfvedsonite, and eu- 
dialyte, the latter in varying and sometimes in very small 
amount. As minor accessories the following minerals have 
been detected: ainigmatite, rinkite, rosenbuschite, molybdenite, 
sphalerite, biotite, polylithionite, and apatite. The micro- 
scope also reveals the presence of analcime and natrolite 
(spreustein) occurring as secondary minerals in the same man- 
ner as in the sodalite-foyaite. A little interstitial analcime is 
often observed. 
The sodalite is very abundant in vell developed dodeca- 
hedra. It is the most idiomorphic constituent of this rock; 
only where it borders upon nepheline it does not show any 
distinct idiomorphic form. The dodecahedral cleavage is well 
developed. The crystals are isodiametric or slightly elongated 
parallel to a trigonal axis. The diameter commonly varies be- 
tween 3 and 5 millimeters; exceptionally very elongated crystals 
