498 PROFESSOR HEDDLE ON THE MINERALOGY OF SCOTLAND. 
stances which had heen considered chondrodite ; but which, answering neither | 
to the description of that mineral nor of any other, was examined and analysed. 
It occurred, so far as our observations went, only at the spot mentioned ; 
and, of another colour, at a second spot afterwards to be noticed. Imbedded 
in the granular limestone surrounding the malacolite, were granules up to the 
size of peas, of a substance which bore a certain amount of resemblance to. 
chondrodite, but which was so identical in appearance to danburite as to be 
almost undistinguishable. The quantity of material unfortunately was so small 
that it had to be picked for analysis under the microscope ; and even then, 
adherent, or rather imbedded malacolite, could not be absolutely removed. Its 
colour was pale fawn ; its lustre weak and glimmering; it was slightly softer 
than danburite; it had distinct cleavages, but also a conchoidal fracture; it was 
surrounded in the limestone by imbedded granules of yellow, green, and dark- 
=, 
grey serpentine. 
Its occasionally investing granules of malacolite leads to the impression 
that it may be a product of their change. As the surrounding granules of 
serpentine were frequently in the form of augite, there could be no question 
as to them ; the associated blue malacolite, however, was perfectly unaltered, — 
as were the specks of colourless malacolite imbedded in the mineral. The 
mineral in itself also did not resemble an alteration product. ¢ 
1: 303 grammes yielded— 
Silica, : ; .48 ‘ 
From Alumina, . °005 Mi 
*485 = a7 ° 221 i. 
Alumina, . ‘ ¢ : a7 ou < 
Ferrous Oxide, . 4 sp dhe 045 4 
Manganous Oxide, . : °23 2 
Lime, : : ; eee : 
Magnesia, . . 44°973 ; 
Water, . : : . 10-6438 
Insoluble silica, 1 - 422 per cent. 
27. Immediately to the south of the pier at Totaig, the limestone thrusts — 
itself as a rounded bluff into the sea; projecting from its corroded surface are 
numerous confusedly crystalline segregations of malacolite, and very rarely 
among these, the same mineral as that already described, differmg in no~ 
respect from it, except in its having a blue-black colour, and a somewhat — 
higher lustre. It was here found in masses of some size; it occasionally 
invested the crystallised malacolite, the structure and lustre of both being — 
similar. 

