62 PROFESSOR HEDDLE ON THE MINERALOGY OF SCOTLAND. 
It occurred in a highly tortuous vein, which, with its veinstone, was about six 
feet wide. This vein runs in a general sense along the strike. 
A considerable quantity of penninite lay about the old workings, but pure 
pieces were rare ; it was also associated with picrolite and “ baltimorite.” 
The first specimen I saw I obtained from the dealer Doran, who sold it as 
Leuchtenbergite: this differed from any specimen I have seen either on the 
spot or elsewhere in Scotland. It consisted of a band or layer of foliated 
crystals of half an inch or more in thickness, said crystals lying transverse to 
the sides of the layer. Its colour was leek green. The specimens I obtained 
on the spot were of a dark-green colour: they all consisted of masses of 
foliaceous crystals of half an inch in size, but these all lay in parallel arrange- 
ment with the rock matrix. Their lustre was high, and not pearly. Specific 
gravity, 2 : 895. 
1-542 grammes yielded— 
Silica, : ‘ * 505 
From Alumina, . * 024 
* 529 = 34° 306 
Alumina, , : » 18°64 
Chromium Sesquioxide, . _ trace 
Ferric Oxide, . : . * 364 
Ferrous Oxide, ‘ ; 6.10 305 
Manganous Oxide, . ‘ 227 
Lime, . , ‘ : 8°97 
Magnesia, ; : . 18:°041 
Potash, . : ‘ : 1°36 
Soda, 4 ‘ ‘ : lies 
Water, . : : ie saline 
oo 75 
Insoluble silica, 6:79. Was apparently quite pure. 
3. Kammererite.—This chromiferous variety I first found in Britain in the 
year 1848. It occurred in a granular massive form in considerable quantity in 
the great quarry of chromite at Hagdale in Unst, Shetland. Its colour is 
purple to bluish purple. It ordinarily contains nodules of the size of shot, 
which are quite granular, and probably differ in composition. These were 
removed. Rarely it is foliaceous, and still more rarely regular imbedded 
hexagonal crystals are to be seen; these are less than a quarter of an inch in 
size. They are pale violet in colour, and sometimes light green. They are 
readily cleavable into thin folie. 
Of the massive variety, which was analysed, the specific gravity is 3-099. _ 
