488 



Orjesogno-cuitistance which will olwr.ys render It improper to use 4. As.ynl.The following varieties of marble found 

 such varieties m a common kiln. But the most import- 



ant use of this mineral is as marble. These marbles 

 have been known from a very early period ; and an- 

 cient statuaries have immortalised their names, by the 

 master-pieces of art which they have executed in them. 

 Of the ancient marbles, the most celebrated are those 

 of Paros, Pentelicus, and Carrara. Marbles of different 

 descriptions occur jn Scotland, England, and Ireland, 

 as appears from the following enumeration. 



Scottish Marbles. 



Scottish .The Marbles of this part of Great Britain have 

 Marbles, hitherto been but little attended to, although it is high- 

 ly probable that many valuable varieties occur in the 

 different primitive and transition districts. At present, 

 we shall mention a few of the best known varieties. 



1. Tiree Marble Of this marble there are two va- 

 rieties, viz. the Red and White. 



a. Red Tiree Marble This is one of the most highly 

 prized of the Scottish marbles. Its colours are red^ of 

 various tints, such as rose-red and flesh-red ; also red- 

 dish-white: its lustre is glimmering ; and the fracture 

 is minute foliated, accompanied with splintery. It is 

 very faintly translucent, or only highly translucent on 

 the edges. It is always intermixed with different other 

 earthy minerals, that add to its beauty, and give it a 

 peculiar appearance. The most frequent of the im- 

 bedded minerals is common hornblende; the others 

 are pale-green sahlite, blackish-brown mica, and green 

 chlorite. In some varieties the hornblende is so abun- 

 dant, that at first sight they might be confounded with 

 syenite: in others, where nearly the whole mass is of 

 hornblende, it would be considered as a variety of 

 hornblende rock. 



6. White Tiree Marble. Its colours are greyish- 

 white and bluish-white: it contains scales of mica, and 

 crystals or grains of common hornblende ; which latter, 

 when minutely diffused, give the marble a green or 

 yellowish-green colour, and when very intimately com- 

 bined with the mass, form beautiful yellowish-'Teen 

 spots. 



2. lona Marble Its colours are greyish-white and 

 snow-white. Its lustre is glimmering, and fracture 

 minute foliated, combined with splintery. It is harder 

 than most of the other marbles. It is an intimate 

 mixture of limestone and tremolite; for if we immerse 

 it in an acid, the carbonate of lime will be dissolved, 

 and the fibres of tremolite remain unaltered. It is 

 sometimes intermixed with steatite, which gives it a 

 green or yellow colour, in spots. These yellow or 

 green-coloured portions receive a considerable polish, 

 and have been erroneously described as nephritic 

 stone, and are known also under the name of lona or 

 IcolmkiU Pebbles. The marble itself does not receive 

 a high polish: this, with its great hardness, have brought 

 it into disrepute with artists. Several of the varieties 

 of lona marble are dolomite. 



MINERALOGY. 



4. Assynt 1 



in Sutherland, have been introduced into commerce by 



Mr. Joplin of Gateshead. 



a. White marble, which acquires a smooth surface 

 on the polisher, but remains of a dead hue, like the 

 marble of lona : hence its uses as an ornamental mar- 

 ble are much circumscribed. 



6. White mottled with grey, and capable of receiving 

 a high polish, and is not deficient in beauty. 



c. Grey coloured, and highly translucent and crys- 

 talline, and capable of being applied to the purposes 

 of ornament in sepulchral sculpture. 



d. Dove-coloured, compact, translucent, and receiv- 

 ing a good polish. 



e. Pure white, and translucent, and capable of being 

 used in plain ornaments ; but too translucent for sculp- 

 ture. 



f. White, with irregular yellow marks, from being 

 intermixed with serpentine. It is very compact. 



g. White variety, with layers of slate-spar. 



5. Glen Tilt Marble The limestone of Glen Tilt, 

 first mentioned by Dr. Macknight, in his description of. 

 that valley, has of late attracted the notice .of the 

 Duke of Athole, through the suggestion of Dr. M'CuU 

 loch. The marbles are white and grey, and veined or 

 spotted with yellow or green : they vary in the size of 

 the grain or concretion, and also in tne degree and 

 kind of polish they receive. 



6. Marble of Ballichulish This marble is of a grey 

 or white colour, and is very compact. It may be raised 

 in blocks of considerable size. 



7. Boyne Marble Its colours are grey or white, 

 and it receives a pretty good polish. 



8. Blairgojvrie Marble. Mr. Williams, in his Natu- 

 ral History of the Mineral Kingdom, mentions a beau- 

 tiful saline marble, of a pure white colour, which oc- 

 curs near Blairgowrie in Perthshire, not far from the 

 road side. According to him, it may be raised in 

 blocks and slabs, perfectly free of blemishes, and in 

 every respect fit to be employed in statuary and orna- 

 mental architecture. 



p. Glenaven Marble, is of a white colour, and the 

 concretions are large granular. It is menrioned by 

 Williams as a valuable marble ; but he adds, that its 

 situation is remote, and difficult of access. 



English Marbles. 



Hitherto but few marbles of granular foliated lime- English 

 stone have been quarried in England ; the greater Alarblts. 

 number of varieties belonging to the floetz or second- 

 ary limestone. One of the most remarkable of the 

 English marbles of the present class, is that of Angle- 

 sey, named Mona MarLle, which is not unlike the 

 Verde Anlico. Its colours are greenish-black, leek- 

 green, and sometimes purple, irregularly blended with 

 white ; but they are not always seen together in the 

 same piece. The white part is limestone : the green 

 shades are said to be owing to serpentine and asbestus. 



3. S/eye Marble In the Island of Skye, in the pro- The Black Marbles found in England, are varieties of 

 perty of Lord Macdonald, there are several varieties of Lucullite. 



Irish Marilcs. 



marble, deserving of attention, inclosed in porphyry, 

 sandstone, and trap-rocks. One variety is of a greyish 

 inclining to snow-white colour : another greyish- white, 

 veined with ash-grey ; and a third is ash-grey, or pale 

 bluish-grey, veined with lem O n-yellow or siskin-green. 

 Dr. M'Culloch has described other varieties; and more 

 minute details are expected from his promised work on 

 the "Geology of the Hebrides," 

 3 



The Black Marbles of Ireland, now so generally Irish Mar- 

 used by architects, are Lucullites. TB the county of bles - 

 Watertbrd, different kinds of marble are known; thus 

 at Toreen, there is a fine variegated sort, of various 

 colour', viz. chesnut-brown, white, yellow, and blue, 

 and which takes a good polish : a grey marble, beauti- 



