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Mineralogy of the Islands of Arran, as collected from a few specimens in the Museum 
of the Royal Dublin Society. 
THE Islands of Arran consist mostly of grey and greyish-black Lime-stone of 
different descriptions: it is partly compact, partly granular. The compact contains 
some petrifactions, particularly Chamites, Cochlites, and Anomites. Some part of 
this Lime-stone is of a slaty texture. In some large blocks along the shore, which 
have the appearance of reddish-grey conglomerats, there are imbedded small im- 
perfect Madreporites. Some parts of the greyish-black Lime-stone is bitumi- 
nous, and emits a strong hepatic smell, when struck with ahammer. This kind is 
sometimes decomposed on its surface, and passes into calcareous Marl-slate. It con- 
tains, but rarely, common pyrites, partly in grains, partly in cubes. Some of these 
compact Lime-stones, particularly those of greyish-black colour take, a very fine 
polish. 
Fine granular Green-stone is also found in very large ‘Maasses, generally \ron- 
shot on its surface, and decomposed: it forms a yellowish-brown Iron-ochre. 
Nodules and Boulders of common Iron-pyrites, of a pale brass-yellow colour, are 
found imbedded in compact greyish-black Lime-stone, and loose. “ 
Meadow Iron-ore, of a yellowish-brown and ochre-yellow colour, is found in loose 
pieces. 
Blue Iron-earth, or blue Phosphate of Iron of pulverulent particles, occurs in 
Turf-lJand, but rarely. 
