PROFESSOR HEDDLE ON THE MINERALOGY OF SCOTLAND. 77 
Structure foliated. Was in rough lozenge-shaped crystals, which were appa- 
rently monoclinic. Brittle. 
Hardness, 5°5 on the cleavage plane, 6° on the lateral. Specific 
gravity, 3° 356. 
On 1-305 grammes— 
Silica, ; ; = 2002 
From Alumina, . 029 
eo) = 25 * 363 
Alumina, . J | . 41°736 
Ferric Oxide, . , SeVsrso5 
Ferrous Oxide, . ‘ £3 932. 
Manganous Oxide, . . “O19 
Lime, ; ; A ; "901 
Magnesia, . ; : ss O32 
Water, . , : hel inisy al 
100° 137 
Insoluble silica 4 * 58 per cent. 
2. The above analysis having disclosed the nature of the substances which I 
had regarded as that which had been by some considered Babingtonite, I 
found upon breaking up masses of the rock that deeper-seated crystals were of 
a fine dark-green colour ; and during a late visit to Shetland, in company with 
Mr Dupceron, I refound the mineral, and was thus enabled to examine perfectly 
unaltered specimens. 
These we obtained at the same spot, imbedded in reddish vitreous massive 
quartz-veins of mica slate, associated with margarodite and pale yellow sphene. 
The colour was dark green, the lustre shining and pearly, the streak pale 
greenish-grey. The specific gravity from 3° 313 to 3° 462. 
24 - 3 grains yielded— 
Silica, ‘ . 5° 746 
From Alumina, -2 
5: 946 = 24:47 
Alumina, ; : 2) GA 330 
Ferric Oxide, . : : * 383 
Ferrous Oxide, : fon Loe o22 
Manganous Oxide, : pail 
Lime, , : . : * 302 
Magnesia, , ; : 6°8 
Water, . ‘ : d 6°98 
Insoluble silica, 3 66 per cent. 
