small lumps which have probably originated by magmatic re- 
sorption of eudialyte!. 
Structure. — The structure of the arfvedsonite lujavrite 
(see Fig. 18) is of the trachytoid type owing to the bath-like 
form of the felspar, and there is a more or less pronounced 
tendency toward panidiomorphic development. The typical va- 
rieties of this rock show a conspicuous flow-structure and 
a corresponding schistosity. The felspar-crystals are not seldom 
seen to be curved or broken but the arfvedsonite columns 
never show any sign of deformation. On the other hand the 
flow-structure is not so pronounced as that of the typical 
egirine-lujavrite described above, and in many places the rock 
gradually passes into more or less massive varieties. 
Chemical composition. — To illustrate the chemical com- 
position of the arfvedsonite-lujavrite two typical specimens have 
been analyzed and the results are shown below in columns 11 
and 12. The first specimen, of which an analysis is given in 
11, has been taken at Lille Elv, Kangerdluarsuk. In the slices 
the mineral composition is seen to be the following: arfvedso- 
nite, ægirine, albite, microcline, nepheline, sodalite, and minor 
accessories. The albite-crystals are present in greater amount 
than the microcline-crystals; ægirine is relatively abundant 
while zeolites (analcime and hydronephelite) are only found in 
small quantities. The second analysis (12) is of a specimen 
from Nunasarnak. Externally both specimens are alike, but 
upon microscopical examination the latter specimen proves 
richer in arfvedsonite and poorer in egirine. 
For purposes of comparison the mean composition of the 
analyses of the Greenlandic egirine-lujavrite (analyses No. 8, 9, 
and 10, see p. 168) is given in A, and it will be seen that 
the chemical composition of the arfvedsonite-lujavrite is of 
the same general character as that of the ægirine-lujavrite but 
1 Meddelelser om Grønland XIV, р. 172 (1894). 
