7 
462 PROFESSOR HEDDLE ON THE MINERALOGY OF SCOTLAND. 
Coccolite. 
From Gneissose Rocks. 

9. In association with limestone. 
Dr Joass sent me from the Gruagach Cliff, near Loch Ailsh in Ross, a lump 
of coccolite passing into cleavable augite. 
The colour was deep, rich green. The portion upon which the specific 
gravity was taken was probably somewhat porous ; it gave 3° 048. 
1-303 grammes yielded— 
Silica, ; ; *627 
From Alumina, . -012 
*639 = 49:04 
Alumina, . : . 6:086 
Ferric Oxide, . é » = i Oe 
Ferrous Oxide, . 2°939 
Manganous Oxide, . : *46 
Lime, , : ; . 20 "S00 
Magnesia, . . : .  tevedds 
Potash, . : 3 : *816 
Soda, ; : ‘ - "(91 
Water, . : ; : °174 
100* 153 
Of the silica, 4° 381 per cent. were insoluble ; possible impurity, margarodite. 
A more typical coccolite or granular Funkite occurs with cinnamonstone in the 
limestone of Delnabo, Glen Gairn. A sufficiency for analysis could not be got. 
Diallage—* Thin foliated Augite.” 
(Ca, Mg, Fe), (Si, Al). 
From Metamorphic Rocks. 
10. From the diallage rock of Unst, Shetland. 
Here the rock is palpably metamorphic. Regularly interstratified among 
bedded rocks a little north of Loch Trista in Fetlar, it sweeps northward 
conformably along with them, with a strike gradually curving to the east, till 
they leave the shores on the north of the island. Reappearing in due course 
to cross the island of Uya, they again appear on the southern shore of Unst, 
trending more easterly still, until they shade off into the serpentine of the north 
of Balta Sound,—the greatest mass of that rock in Scotland. 

