152 
land. It is present in a specimen of naujaite from Nunasarnak 
in colourless (or slightly yellowish) needles and slender prisms 
reaching a maximum length of 2 millimeters. Most of them 
are included in the outer zone of the sodalite-crystals. The 
needles are monoclinic and elongated parallel to the b-axis. 
There is a very distinct longitudinal cleavage. The optic axial 
angle is large. The refractive power, the birefringence, and 
the general habit agree with those of the rosenbuschite from 
Langesund. In several slices of the naujaite a few small crystals 
are observed showing characters agreeing with those of schi- 
zolite, a mineral which has been found in the pegmatites of the 
naujaite!; no exact determination, however, could be made of 
these crystals. 
Structure. — The photograph, Pl. XVII, showing the sur- 
face of a naujaite cliff near the inner end of Kangerdluarsuk 
Fjord, will give a general idea of the peculiar poikilitic struc- 
ture of this rock. The rock may be said to be made up of a 
hypidiomorphic aggregate of felspar, nepheline, eudialyte, ægirine, 
and arfvedsonite. This aggregate is exceedingly coarse-grained 
(the length of the individual crystals with exception of the 
nephelines commonly exceeds 10 centimeters), and all crystals 
of the aggregate are closely and uniformly dotted with dode- 
cahedra of sodalite averaging half a centimeter across or a little 
less. This contrast as to size between the sodalite and the 
other constituents is always very conspicuous: the sodalite- 
crystals never show the slightest tendency to attain dimensions 
comparable with those of the other minerals”. The bearing of 
this structure on the question of the origin of the naujaite will 
be discussed in the last chapter. 
1 0. B. BössınLn, On some minerals etc. Meddelelser om Grønland XXVI, 
1903, p. 121. 
2 This refers exclusively to the naujaite itself: in the pegmatitic veins of 
the naujaite the same minerals may be present and the sequence of 
crystallization may be the same as in the naujaite but the structure is 
entirely different (p. 65). 
