173 
but owing to the very small dimensions of the grains I have 
not been able to identify them with certainty!. — The slices 
of the specimens from Lille Elv (the same specimens of which 
a chemical analysis is given below) contain grains of a some- 
what altered mineral which bears some resemblance to the 
olivine when in an advanced state of serpentinization (with mesh- 
Fig. 1S. Arfvedsonite-lujavrite, Nunasarnak; >< 20. 
Showing nepheline (white), felspar (light gray), eudialyte (small and well-defined 
crystals), and arfvedsonite (longitudinal sections black and transverse sections 
dark gray). 
structure’); the mean index of refraction, however, seems to be 
a little lower than that of olivine. — Finally it may be men- 
tioned that zircon has been observed in one specimen of this 
rock (from Nunasarnak); it is in minute grains crowded in 
1 The chemical composition of the erikite (Meddeleser om Grønland XXVI, 
p- 104) is approximately that of a mixture of two thirds of monazite and 
one third of hydronephelite. 
