242 PROFESSOR HEDDLE ON THE MINERALOGY OF SCOTLAND. 
From a Vein in vicinity of Serpentine. 
3. Barra hill, in the vicinity of Old Meldrum, in Aberdeenshire, is composed 
of an almost black serpentine which contains, porphyritically inbedded, patches 
or spots of apparently a highly altered felspar ; giving much the appearance of — 
an amygdaloid. 
This serpentine indeed famines an igneous rock more than any in the 
north of Scotland, with the one exception of that occurring near the railway 
station at Rothiemay. 
A low spur or ridge is thrown out by the hill on its south-west flank pointing 
in the direction of Premnay, which is the nearest spot at which serpentine 
occurs to the west. About half-way up the ridge a quarry has been opened | 
for dyking purposes—this quarry contains veins of granular labradorite, which 
in their fissures show radiating crystals of Wollastonite. 
A dyke built out of this quarry and flanking its side, contained a mass 
which was apparently a portion of a vein, which might have lain either between 
the serpentine and the adjacent gneiss, or have cut the gneiss itself. | 
This mass consisted of a pale blue vitreous quartz, a little muscovite, and 
the oligoclase analysed; this was much run through with quartz, from which 
it was with difficulty separated. 
Colour, milk white; no strie. Cleavage angle from 86° 8’ to 86° 18’; specific 
gravity, 2°834. This high gravity led to its being considered labradorite, not- 
withstanding its association with quartz and muscovite. 
1-302 grammes yielded— 

Silica, : A . °* 834 
From Alumina, : “008 
842 = 64°67 
Alumina, . rage 4s 22-18 4 
Ferric Oxide, . i a » howler 5 a 
Magnesia, i bel ae [01 . 
ame,” ENE) 2 Car 893 
Potash, ~. 4 : ta Bass 
Soda, : f ; Pai tad oY. 54 
Water, . : 3 : ab " 
99-529 | 
Tnsoluble silica, 5:76 per cent. ; s possite perhaps proba impurity, a trace | 
of quartz. 7 
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