The Mineral Resources of Greenland. 57 . 
felspar, occurs in vertical tabular bodies up to 0.75 m (2!/, feet) wide, 
which cut without gradation a normal biotite-garnet-quartz-felspar- 
pegmatite, containing, in places, graphite. Here two rocks evidently 
solidified from the pegmatitic fluids. The muscovite plates which are 
oriented in all directions reach a maximum diameter of 20 cm (8 inches). 
Some are smooth, others bent or “ruled””, but, on the whole, the quality 
is rather good. 
Semi-precious and ornamental stones. 
Cordierite. 
Cordierite is a constituent of normal quartz-felspar-pegmatite dikes 
on Upernivik and Langø (Long Islands) (latitude 72°47’). It also occurs 
in irregular masses up to 4 cm (11/, inch) in diameter in the graphite 
at Long Island, also believed to be of pegmatitic origin (see p. 42). 
With it are associated yellow cyanite, red garnet, quartz, felspar, biotite 
and pyrite. In one direction, the color is a fine, deep bluish violet, 
in the other, gray. Stones cut of this cordierite are of pleasing color 
in certain lights, although of little brilliancy. Cordierite is reported by 
GIESECKE from Ujordlersuak island (74° N. latitude) and also occurs 
in the granite gneisses at Sermersok and Nanortalik near the south 
end of Greenland?). 
Spinel 
of a steel-blue color occurs in octahedra up to 1.25 cm (#/, inch) in 
diameter in the crystalline limestone bands from Isortok fiord north. 
Beryl 
(bluish) occurs at several places in the pegmatite and is of rather good 
color, but is only semi-transparent. 
Tourmaline 
of gem quality does not occur in the pegmatites, although the black 
tourmaline crystals from Ameralik fiord were according to THOMAS 
ALLAN (THomson, “Annals of Philosophy”, Vol. 1 1813, p. 105) prized 
by mineralogists over 100 years ago. 
Amazonstone 
and moonstone of poor quality occur in the pegmatites at several local- 
ities and aventurine!) felspar in granite just south of Puisortok glacier, 
about 61°55’ on the east coast and at several other localities. 
1) EBERLIN: Medd. om Grønland, vol. IX р. 251, Copenhagen, 1889. 
