All across Ireland, from the Ballyhoura Hills on the Cork border to the southern shore of Belfast Lough, slaty and sandy Silurian beds appear in the axes of the anticlinal folds, surrounded by Old Red Sandstone scarps or Carboniferous Limestone lowlands.
Although called blue, the colour is a slaty or drab tone.
An exquisite gem is I. r. cyanea, which is very bright in color, a slaty blue, and dwarf.
Blue mud, according to Murray and Renard, is usually of a blue or slaty or grey-green colour when fresh, the upper surface having, however, a reddish tint.
Buffaloes of an uncouth appearance and of a dark slaty color, strikingly contrasting with the neat cattle, abound in Egypt.
From the name schistos, and the mode of formation, there can be little doubt that this species was the salt which forms spontaneously on certain slaty minerals, as alum slate and bituminous shale, and which consists chiefly of the sulphates of iron and aluminium.
In 1854, after the meeting of the British Association in Liverpool, a memorable visit occurred to the Penrhyn slate quarries, where the question of slaty cleavage arose in his mind, and ultimately led him, with Huxley, to Switzerland to study the phenomena of glaciers.
In a second phase of the species, the colour, which often displays a slaty hue (whence the name of blue fox), remains more or less the same throughout the year, the winter coat being, however, recognizable by the great length of the fur.
In colour Anopheles is usually brownish or slaty, but sometimes buff, and the thorax frequently has a dark stripe on each side.
It is thought that certain beds of slaty rocks, which have been recognized at different places, may belong to some of the Primary strata.
It occurs crystallized, commonly in cubes, in schistose and slaty rocks, and less abundantly in the younger sedimentary deposits.
Lichens for the herbarium should, whenever possible, be sought for on a slaty or laminated rock, so as to procure them on flat thin pieces of the same, suitable for mounting.
The colour is a slaty black; the hide is immensely thick, with scanty hairs.
The flowers are 2 to 3 inches across, deep blue with a slight slaty shade, and in clusters at the end of each branch.
The origin of slaty cleavage is in some measure obscure.
There are few tarns on the slaty, rocks north and west of Keswick, which weather differently giving smoother, gentler scenery.
They are at a depth of about 12 ft., in slaty shale containing Llandeilo fossils and contemporaneous felspathic ash and scoriae.