38 PROFESSOR HEDDLE ON THE MINERALOGY OF SCOTLAND. 
the junction of the bed with the gneissose matrix. At Crathie, in similar 
association. In the great bed which traverses the country down Dee side, it 
occurs here and again, as in the openings on the Leac Ghorm Hill, in Boultshoch 
quarry near Abergeldie, and in Craigs, Muir, and Midstrath quarries—in all 
bemg imbedded in a granitic belt very similar in appearance to that at Glen 
Urquhart ; this belt is, in the three last quarries, composed of little quartz, 
much fatty lustred white orthoclase, and little of the mineral itself. 
It is likewise found in the limestone of Froster Hill, near New Meldrum ; 
along with blue malaccolite, near lime, at Allt-Cailleach, Coyle Hills; along 
with zoisite, pyrrhotite, sahlite, and the usual lime minerals, at Dulnan Bridge 
south of Grantown ; and along with similar minerals and cinnamonstone at Allt- 
na-Gonolan, in the same neighbourhood—at both localities in limestone. 
Its occurrence with ripidolite at Hillswick, near the junction of what has 
been called hornblendic gneiss with micaceous rocks, is somewhat exceptional ; 
but that first-named rock, which I shall elsewhere describe, is new to me. 
Biotite is thus seen to occur generally associated with granular limestone. 
This is probably also the dark mica which occurs as an accessory mineral in 
hyperyte and tufa. It is nowhere associated with another mica. 
Passing to Haughtonite, we find it, in the specimens analysed, a component 
of granitic ves, whether these be intrusive or exfiltrative. Extending the 
evidence, it is to be noted as occurring in specimens equally characteristic with 
the above, in Rubislaw, Anguston, Sclattey, and other quarries in the “grey 
granite,” and the large, distinctive crystals are always in the veins. 
At Blirydrine, Brathans, and many other places, it is seen in the felspathic 
bands of the gneiss. 
In these situations it may be regarded as replacing muscovite, which very 
rarely, as at Cove, accompanies it. In every case where it occurs in exjiltra- 
tion veins, oligoclase is also present; less frequent associates are sphene, 
Allanite, and in one locality (Anguston) ilmenite ; what may be called chance 
associates are beryl, apatite, tourmaline, and garnet. 
But besides its position in the exfiltration veins of the grey granite, it goes 
largely to form the mass of that rock itself. Ifthe word granite be confined to 
a compound of quartz, orthoclase, and muscovite, then must “ grey granite ” 
lose all title to the name; for though quartzose in spots, as a rule it contains 
comparatively little quartz, hardly any muscovite, and not the excess of ortho- 
clase normal to granites,—being composed in greatest bulk of oligoclase, 
quartz, and Haughtonite, with smaller quantities of orthoclase. The distinctive 
feature of the rock is the large quantity of this black mica. 
In the ascertaining the nature of the dark mica of grey granite, it will not 
suffice to evade the trouble of picking out the minute scales from the general 
mass of the rock, by making use, instead thereof, of a portion of those curious 
