454 PROFESSOR HEDDLE ON THE MINERALOGY OF SCOTLAND. 
Amianthus. Chlorite, rare. 
Pyrite, rare. Orthoclase, rare \ : 5 k 
; in covering rock, 
Tale, very scarce. Haughtonite ? ee 
Steatite, rare. 
The sahlite is found of two very different colours: the more common, a pale — 
leek-green ; the rarer, a very dark green. These three varieties of the same 
mineral—the malacolite, the sahlite, and the augite—in no way pass into one 
another ; they are perfectly different in appearance, and the malacolite some- 
times occurs in cavities in distinct crystals, which are super-imposed upon the 
sahlite. An augitic asbestus rarely occurs also. Another point of note here 
is the paragenetic occurrence of the hornblendic type of mineral, which also 
presents itself in three varieties, which do not shade into one another— 
amianthus, tremolite, actynolite. 
The lime carrying these minerals is highly granular, but for the most part 
dense ; it shows rarely a belt or belts of a brilliant red. Two beds, separated 
only some half dozen feet, occur; they dip at an angle of about 20° to the 
north ; they are immediately overlaid by ordinary gneiss, but this in turn under- 
lies a bed of hornblende rock ; and the gneissic beds which overlie this are for 
some distance persistently hornblendic. 
Somewhat south of the line of strike, the same beds of lime, with the same 
dip, appear at Arskaig, on the south side of Loch Shin, but only for a short 
distance ; they lie between two cross faults. 
The malacolite is of a white colour, a cleavage angle of 87-5, and specific 
gravity, 3°149. 1°306 grammes yielded— 
Silica, 5 : - 688 
From Alumina, . *005 
"693 = 53° 062 
Alumina, . , ; : “195 
Ferric Oxide, . . Main Ga A (2° 
Ferrous Oxide, . , ; "Al 
Manganous Oxide, . : *153 
Lime, : : : .. 2° 626 
Magnesia, . : , S19 > 295 
Water, . : : oo 6 
100:118 
Insoluble silica, 2°741 per cent.; the specimen was absolutely pure, the 
only contact mineral being lime. 
The ¢ cleavages of the malacolite and sahlite of Shinness, and of the mala- 
colite of Scotland generally, is so eminent that the crystals fall asunder along 
it frequently in being extracted; yet this cleavage is not even mentioned in 
Brooke and MILter’s “ Mineralogy.” 

