PROFESSOR HEDDLE ON THE MINERALOGY OF SCOTLAND. 95 
In order to be enabled to contrast the composition of the saponite 
from this locality with that of the celadonite, the former was picked 
from the centre of those cavities in which it was invested by the opaque 
celadonite. 
The mineral here is very translucent, devoid of structure, much flawed, 
resembles a green wax, has a somewhat brownish-green tint, and is easily 
bruised by the nail. 
Its specific gravity is 2 283. 
25 grains yielded— 
Silica, ; ’ , , 0 Ed 
Alumina, . : ¢ . 6:49 
Ferric Oxide, . : yy Er Ge 
Ferrous Oxide, . 5 5 Bae) 
Manganous Oxide, . ‘ trace 
Lime, : : : . 2°008 
Magnesia, . A : . 21° 666 
Potash, . 4 : é ob 7A 
Soda, P ’ 5 2 Spall 
Water, i : , wee 1ei6 
100 : 387 
Loses in bath 13 - 96 of the above water. I have lately found the mineral 
| at this locality in thin veins, with a pseudo-fibrous structure due to interstitial 
| fibrous calcite: in this form it is indistinguishable from the “ Bowlingite” of 
| Bowling Quarry. 
In the foundation rock of Broughty Castle, on the north side of the Tay, 
| saponite occurs both filling druses as a matted mass of fine scales, and also 
merely lining the druses in “rosettes” of minute crystals. These are of a 
_ brilliant dark-green colour, and in hexagonal combinations, apparently grouped 
_ like ripidolite. Their extreme softness is the only physical property by which 
they can be distinguished from that mineral. Their content of water at once 
| determines their nature. In Roy Quarry, in Broughty Ferry, saponite occurs 
in quantity both in veins and filling small druses. 
7. “ From the Catkin Hills,” in Lanarkshire.—This was given to me by the 
late Toomas Brown, Esq. of Lanfine.‘ It occurred filling small druses in a dense 
igneous rock; its structure was minute scaly; its colour a bright green ; 
when bruised or scratched the streak is nearly white; its specific gravity is 
2 + 279. 
VOL. XXIX. PART I. 2B 
