28 PROFESSOR HEDDLE ON THE MINERALOGY OF SCOTLAND. 
From Intrusive Veins in Geiss. 
7. The following specimen was found by Mr James WItson of the Geological 
Survey, and I examined it at Professor GEIKIE’s request. 
It was imbedded in a very pale lavender almost white orthoclase, which 
forms a vein which in a semicircular curve cuts the schists to the north of the 
Kinnaird Head lighthouse. 
The orthoclase is interesting not only from its rare colour, but also from its 
showing in an unusually distinct manner, the structure described by me in my 
paper on the felspars,—it is probably DESCLOIZEAUX’ microline. 
Radiated cleavlandite is imbedded in bundles of divergent crystals at the 
surfaces of the orthoclase ; its colour is the same, or somewhat paler. 
The mica is in foliz of half an inch in size. It is black in mass. but when 
cleaved thin it has a fine, dark, grass-green colour. It is very slightly biaxial. 
It powdered with unusual facility, being brittle. Its specific gravity is 3°126. 
1-2 grammes yielded— 
Silica, . : : ‘42 
From Alumina, . ‘008 
‘428 =s 35° 666 
Alumina, 7° 94:7 
Ferric Oxide, tuo. 
Ferrous Oxide, 18-063 
Manganous Oxide, 26 
Lime, 1°4 
Magnesia, Le, 
Potash, 9° 273 
Soda, . ayano 
Water, ao 
100°05 
The portion examined seemed quite pure: the possible impurity was the 
felspar, in which it was imbedded. 
This specimen is remarkable on account of the small quantity of magnesia 
which is present. 
From Intrusive (?) Veins in Granite. 
8. From the granite quarry of Cove, Kincardineshire. Occurs in veins, in 
elongated crystals, which lie frequently imbedded in and parallel to the 
