
216 PROFESSOR HEDDLE ON THE MINERALOGY OF SCOTLAND. 
The vein from which the orthoclase was taken contains also little quartz, 
crystals of orthoclase and oligoclase in about equal quantity,—the crystals of each 
being about two inches in length and breadth,—large crystals of green Haugh- 
tonite, the largest crystals of Allanite yet got in Scotland, and crystals of sphene, 
of sometimes half an inch in size, which much resemble Keilhauite in colour and 
lustre. 
There was also in cracks a minute quantity of a purple substance, much 
resembling yttrocerite, but which more probably was fluor: it did not lose 
its colour when heated. 
The orthoclase was of a pale pinkish tint ; its cleavage angle, 89° 59’; its 
S. G. 2° 555. 
25 grains yielded— 

Silica, : ; . 14°898 
From Alumina, ‘ * 756 
152 654, | = 3 162 ole 
Alumina, . ; é : | £97634 
Ferric Oxide, . ; E : * 064 
Magnesia, . , f : ; * 636 
Lime, : : : : - * 604 
Potash, . : : : adore 
Soda, ; , : , ; 2°92 
Water, ; : : ; : als 

100 ° 324 
1° 305 per cent. of the silica insoluble. Possible impurity, oligoclase. 
9. Amazonstone from a vein in the syenitic granite of the north of Suther- 
land. This white granite is very similar to that at Lairg; as it contains very 
few sphenes, more quartz, and little or no mn it has still less claim 
to be called syenitic. 
I am indebted to Dr Joass of Golspie and Professor Nicox for the fragments 
of this very rare variety of orthoclase which were analysed. Fragments and 
a few crystals of it were sent, as “a pretty green stone from a boulder,” to 
Dr Joass, and deposited by him in the museum of the Duke of SuTHERLAND 
at Dunrobin. To the courtesy of that nobleman the author is indebted for 
the fine crystal, a plate of which accompanies this paper. 
This boulder, doubtless derived from the adjacent mass of Ben Laoghal, 
lay upon the west slope of Ben Bhreck, Tongue. Having been broken up by 
the author for the Duke of SuTHERLAND in the interests of science, it proved to 
be quite a mineral casket. Specimens of amazonstone of unparalleled magni- 
ficence were profusely distributed among an assemblage of minerals occulta 
within the same space, certainly nowhere else in Scotland. 
