38 SYDNEY Н. BALL: 
the head of Sarkak’s Kangerdluarsuk, where the chromite is in part 
coated by secondary chrome minerals. Microscopie examination shows 
that chromite occurs in two ways, Ist, as grains or crystals disseminated 
in dunites, in which case it is usually enclosed in the olivine or other 
constituents of the rock, 2nd, as chromite aggregates in association with 
a white mica, probably muscovite. 
Chromite of secondary origin also occurs in small quantities in 
asbestos (see p. 56). 
Nickel. 
STEENSTRUP!), at Igdlokunguak, north shore of Disco Island, was 
shown by Fritz JORGENSEN, the governor of Ujaragsugsuk, the original 
finder, in 1871, a dike of coarse olivine basalt (presumably the Tertiary 
“peridotite” of this article) from 3—5 m (10 to 16 feet) wide intrusive 
in the coal-bearing sediments. Within the basic rock is a mass of nickel- 
iferous pyrrhotite 3m (10 feet) long, 1.5m (5 feet) wide, and 1.25 m 
(4 feet) thick, which he estimated to weigh about 28 tons. There are 
also, in the dike, numerous nodules and small grains of the same sub- 
stance. The pyrrhotite is stained with zaratite. STEENSTRUP?) revisited 
the locality in 1899 and found the mass covered by rusty brown or 
green (copper and nickel) stains and considerably weathered. This 
STEENSTRUP considered with reason to be a magmatic segregation. 
J. LAWRENCE SMITH?) reports that it contains appreciable copper, 
nickel and cobalt. 
Pyrrhotite is also known from several other localities. 
The Early Tertiary(?) peridotite on the north shore of Nugsuak 
peninsula, is slightly nickeliferous (0.27 according to PHALEN*) and on 
it and on the intruded partially metamorphosed Cretaceous sedimentary 
rocks occur apple-green stains and thin films of annabergite. 
Molybdenite. 
Molybdenite occurs at a comparatively large number of places on 
the west coast of Greenland, although no exploitable deposits are known. 
It is usually a constituent of pegmatite, pegmatitic quartz or coarse- 
grained granite, and, with the exception of insignificant amounts, 
1) К. J. V. Sreensrrur: Vidensk. Meddel. fra den Naturh. Forening, Copen- 
hagen, 1875, р. 304 f., also: NORDENSKIÖLD: Ofvers. Vet.-Akad. Förh. Stockholm 
1870 p. 1070. 
2) К. J. V. Sreensrrup: Meddelelser om Grønland 4. 1883 р. 113. 
— — — - — 24 1900 p. 278. 
3) J. Lawrence SMITH: Annales des Chimie et de Phys. 5 series. t. XVI, 
1819, р. 487. 
4) Smithsonian Miscellaneous Collections, Vol. 45, No. 1486, р. 211. 
