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hundred pieces of granite in the search, but have been equally 
unsuccessful. There can be little doubt, I think, that crystals of 
Sphene, which are found in this granite, have been mistaken for it 
by careless observers, as some of the Sphene crystals, superficially 
looked at, somewhat resemble Zircon in colour and form ; I think, 
too, that broken pieces of Psilomelane must have been mistaken 
for Antimonite, at Kinharvy, although there is little resemblance 
between these two minerals. Although I never found Zircon in the 
Criffel granite, my friend, Professor Heddle, and I were fortunate 
enough to find Allenite in it ; this mineral is sparingly found in 
some of the granites in the north of Scotland. We also found in 
this granite, for the first time in Britain, the rare mineral 
Gadolonite ; it exists very sparingly ; since then we again found 
this mineral in the granite from Ben Loyal, Sutherlandshire. I 
may just allude to an instance showing the importance of being 
able to recognise granites from their enclosed minerals. A gentle- 
man who was engaged in the investigation of the drift beds and 
boulder clays in the north-west of England and North Wales 
wrote to me that he and Professor Bonney had a strong impression 
that many of the boulders in these drift beds had come from the 
south of Scotland, and asked me if I thought I could identify any 
of the granites and rocks from this neighbourhood. I wrote to him 
I should be glad to assist him. He sent me a large number of 
rock specimens from the drift and boulder clays in the neighbour- 
hood of Liverpool and North Wales. I found I could say with a 
great degree of confidence that many of the granites and rocks sent 
were from this district, as I found crystals of Sphene in them, 
and I was quite certain that this was the case when I found, by 
great good fortune, a crystal of Allenite in one of the pieces of 
granite. It was more than a thousand chances to one finding this 
crystal of Allenite, as it is rather a rare mineral to find in our 
granite, even when carefully looked for.* I have never found 
Sphene in the granite of Cairnsmore, but fair specimens of Epidote 
are to be got in the granite quarry near Creetown, and in some 
other localities—generally poor. Amethyst and Smoky Quartz 
(Cairngorm) are found on Criffel and a few other localities. The 
former is very abundant on the west side of Criffel, above South- 
wick House; more sparingly near Dalbeattie. Clear crystals of 
Amethyst, suitable for jewellers’ purposes, are rarely found ; I have 
* “ Quarterly Journal of the Geological Society ” for May, 1883, p. 119. 
