A, M. Finlayson—Ore-bearing Pegmatites of Carrock Fell, 21 
practically free from tungsten-ores. The small size of the veins and 
the sparing quantity and irregular distribution of the ores give no 
promise of ore-bodies of any consequence. As secondary products, 
there appear small quantities of the yellow tungstite (tungstic ochre) 
and molybdite (molybdic ochre). Native bismuth and bismuthinite 
are also recorded from this district, as well as the mineral griinlingite, 
a variety of tetradymite having the formula Bi, 8, Te.? 
The Vein-minerals and their Relations.—The quartz of the veins is 
glassy and crystalline, in coarse granules, and containing scattered 
patches of white mica. The apatite occurs in long striated prisms, 
terminated by the base or pyramids, and its colour varies from pale 
yellow or lemon-yellow to green. An analysis of the mineral gave 
the following result, showing it to be a fluor-apatite :— 
CaO = 54:11 Al, O3 = 0:87 
P20; = 40°56 Fes O3 = 1°05 
F = 2-98 MeO =0-24 
C = 0-66 
Total 100-47 
The vein-mica is commonly gilbertite, of a yellow or greenish tinge, 
frequently associated in flakes with the apatite. In Cornwall, where 
it was first described, this species often occurs as an alteration-product 
of orthoclase,* and in some districts it is pseudomorphous after both 
scheelite and apatite. Here, however, it appears to be of primary 
origin. An analysis of the mineral revealed the presence of 0:92 
per cent. of fluorine. This is of interest, in view of the widespread 
occurrence of fluorine in potash-micas, which has lately been emphasized 
by Mr. J. E. Spurr.* Thus the gilbertite from Ehrenfriedersdorf 
contains up to 1:04 per cent. of fluorine.t The very small quantity 
of fluorine or other ‘mineralizers’ in the Cumberland veins is in 
harmony with the absence of pneumatolytic products. 
The wolframite occurs in coarse bunches embedded in quartz. The 
prism-faces are longitudinally striated, and fairly complete crystals are 
not uncommon, the usual form being a combination of prisms and 
ortho-pinacoid, terminated by ortho-domes and pyramids. The com- 
position of the mineral, as determined by analysis, is as follows :— 
W O3 = 76:24 
FeO = 16°39 
MnO = 6:05 
CaO = 1:05 
Mie @ = —Orilil 
Total 99-84 
The scheelite is white to brownish.yellow in colour, and occurs, 
when crystallized, in tetragonal bi-pyramids. Under the microscope 
it is colourless, and when suitably cut shows its prismatic cleavages, 
p (111) and e (101), intersecting. The individual crystals, as dis- 
tinguished under crossed nicols, are coarse and closely interlocked. 
? Muthmann & Schroeder, Zits. Kryst. uv. Min., 1898, xxix, p. 144. 
> F. H. Butler, Min. Mag., vii, p. 79. 
= ** Geology and Mining Industry of Tonopah’’: Prof. Paper No. 42, U.S. Geol. 
Sury., 1905, pp. 231-3. 
* Frenzel, Jahrb. Min., 1873, p. 794. 
