Without supplying a geological map, and writing twentyfold more copiously than our space will admit, we could not give an adequate view of the distribution of the rocks of Scotland, and of the varieties and structure of its minerals. But from ‘Malte Brun’s and Balbi’s Systems of Geography Abridged: Edinburgh, Adam and Charles Black, 1840,’ we shall extract a summary, which will please the scientific by its clearness, and the popular reader by its wealth of information; and then we shall exhibit in a brief summary the names and localities of all the rarer minerals of the country. “In a general point of view,” says the work referred to, “Scotland may be separated, geologically as well as geographically, into three portions. By passing a line on the map nearly straight, from Stonehaven, through Dunkeld to the middle of the Isle of Bute, and thence with a slight curve to the Mull of Cantyre, we shall have traced the southern boundary of the primary non-fossiliferous system of rocks. Another line, but more irregular than the former, drawn from St. Abb’s-head, passing near Peebles, Abington, Sanquhar, New Cumnock, to about Girvan, will have a general parallelism with the former line, and will have the older greywacke, now named the Cumbrian system, lying to the south, and extending to the borders; while the land included between the two lines comprehends the old red sandstone, and great central coal basin of Scotland.
“I. STRATIFIED ROCKS. – We shall first notice the stratified systems of those three divisions of the country, beginning with the oldest.
“That extensive tract of Scotland which constitutes the northern division, is composed chiefly of Primary Stratified rocks, namely, gneiss, mica slate, chlorite slate, and clay slate, with subordinate masses of hornblende slate, talc slate, and primitive limestone. These, often with granitic centres, rise into magnificent mountains, of which the Grampians form a part. In many of these deposits, particularly in the mica slate, garnets of a brown colour are very abundant. The mountains of the Trossachs, so effectively described by Sir Walter Scott, are chiefly composed of mica slate. In these primary deposits no organic remains have ever been discovered. But these are not the only stratified formations which constitute this extensive district. The old red sandstone fringes the extremities of the land, commencing about Fochabers, on the east side of the Murray frith; extending on both sides of Loch-Ness within a short distance of Fort-Augustus, and then proceeding northwards with a variable breadth through Fortrose, Tain, Dornoch; expanding the whole breadth of Caithness, and constituting the principal formation of the Orkney Isles. On the western side of the mainland, the old red sandstone is deposited in numerous patches on the gneiss formation, as at Loch-Broom, Gairloch, and Applecross. The newer secondary rocks have been but very sparingly observed in Scotland; yet it is rather a curious fact, that the few patches which have been discovered, are superimposed generally on the old red sandstone, and have not been seen reposing in their uninterrupted order in the secondary series. Thus, the lias shales, highly micaceous, and some of the upper beds of the Oolitic system, occur at the mouth of the Cromarty frith, from Dunrobin-castle to the Ord of Caithness; Applecross and other points on the mainland; and in the Western Isles, on the borders of Mull, the south and east of Skye, and near the Cock of Arran, on a small coal deposit. The equivalent of the fresh-water deposits of the Wealds of Sussex, geologically situate above the oolitic group, and below the chalk, is seen near Elgin in Murray, and Loch-Staffers in Skye. In the central and southern divisions of Scotland, those newer groups of rocks have not been detected. In tracing the geological features of the country in the ascending order of the groups, and confining ourselves to the geographical divisions pointed out, we nest come to the Transition or Greywacke system, now divided into two principal sections, – the Lower or Cumbrian, and the Upper or Silurian. So far as is hitherto ascertained, the silurian division is unknown in Scotland, but the Cumbrian rocks, nearly destitute of organic remains, cover the principal part of the great area of the south of Scotland. These greywacke strata stand at high angles of from 60° to 90° from the horizon, and consist chiefly of coarse slaty strata, seldom divisible into thin roofing slates, and often alternating with arenaceous and coarse conglomerates. Amongst these strata limestone is seldom found, and when it is, the quality is inferior. In the division of the island of which we now treat, coal and its accompaniments are known in very few places. Coal is, however, worked at Canoby, and on the borders at the Carter-Fell. The only other rock formation found in connection with the old transition group here (with the exception of igneous rocks), is a red sandstone, ascertained, in some situations, to be the old red, but in some other places, considered to be the new red sandstone, particularly in Dumfries-shire, where the surfaces of the slabs have curious impressions, supposed to be those of the feet of a species of tortoise.
“The Old Red Sandstone and the Carboniferous System. – In the central division is placed the great coal basin of Scotland; but adhering to our rule of marking the successive formations in the ascending order, we shall first treat of the Old Red Sandstone, the most ancient rock in this subdivision of the country. This rock abuts against the line of the primary rocks, and stretches across the whole country, from the German ocean to the Atlantic, pursuing a south-westerly and north-easterly direction. From the northern line of division it stretches south to the frith of Tay, bearing through Dunning near Stirling, Dumbarton, and thence through the Western Isles, Bute and Arran, and is wrapped nearly round the extremity of the mainland at the Mull of Cantyre. The old red sandstone thus forms a long, uninterrupted, and extensive fertile valley. In the north-western part it rises into hills, in the sides of one of which, Uam Vor, are deep and hideous fissures, the effect of some convulsion. It is more irregularly distributed on the southern boundary of the middle division, commencing on the east about Dunbar, and stretching westerly on the line of the transition range of Moorfoot and Lammermoor-hills beyond Middleton, where it is interrupted by a range of trap, but is again found in the country round Lanark. This formation appears to be of vast thickness, especially in the northern part of the division, and may, it is supposed from recent observation, be divided into three portions, the lower, the middle, and the upper beds. In what is considered the lower strata, the remains of fishes have been found in a high state of preservation, and also large scales and other remnants of a sauroid character, such as those of the holoptychus. The well-known Arbroath pavement belongs to the old red sandstone series. The most important group in the central district is the Coal Formation, consisting of limestone, ironstone, freestone, coal, and clays. Its extent from east to west is bounded only by the extremities of the land. To the north it is cut off from the old red sandstone by a range of trap hills, crossing the country from east to west. On the south it is bounded by the greywacke and old red sandstone. Its breadth averages 40 miles, and is in length about 70. The mountain limestone forms generally the basis of this group, though it is frequently found interstratified with other members of the series, and abounds with countless numbers of organic remains. Below the mountain limestone, however, but belonging to the same group, a bed of limestone is worked at Burdiehouse, near Edinburgh, in which the organic remains differ essentially from those of that just named. These remains consist of many of the plants which distinguish the coal formation; but it also includes the teeth, scales, and other bones of fish, which partake of the reptile character, some of which must have been of gigantic dimensions. Small fishes (the paleoniscus, &c.) are also found in a fine state of preservation. The same limestone has been found in other parts of the country, and is of superior quality to the common limestone for mortar, plaster, and the smelting of iron. The clay ironstone is found in beds and nodules, the workable kinds containing from 27 to 45 per cent. of iron. The kind termed black-band is in high request. From this ore a vast quantity of pig-iron is smelted. The coal is found in beds, varying from a few inches to 40 feet in thickness; and one bed in Ayrshire is about 100 feet thick, interrupted only by thin seams of shale from 1 to 3 inches, and is extracted in great quantity, and used as fuel for domestic purposes, the burning of lime, smelting of iron, working of steam-engines on sea and land. One variety, cannel-coal, is of superior quality for the preparation of gas. From the fire-clay are manufactured fire-brick and gas retorts; and the sandstone furnishes an inexhaustible store of substantial and beautiful material for building. These several deposits contain in abundance the impressions of the vegetables which distinguish the carboniferous period; and what is remarkable, the remains of animals, the same as noted as occurring in the Burdiehouse limestone, are found in the shales, and even in the coal itself. In this district, no strata newer than the carboniferous system is known to exist; all is covered over with accumulations of clays, gravels, sands, and soil.
“II. UNSTRATIFIED ROCKS. – Having thus noticed the direction and geographical position of the several stratified formations of Scotland, we now come to treat briefly of the Unstratified System; and in order to bring this department more clearly to the apprehension of the general reader, we must remark, that the unstratified rocks are of igneous origin – they were, in fact, melted volcanic matter, which had burst through the stratified deposits, which were thus elevated into mountain-ranges; the strata being at the same time raised on edge to various angles with the horizon. This being the case, we consequently find that the unstratified follow the same course with the stratified mountains, since the former were the elevating cause of the latter. Now granite, an igneous rock, is more generally found connected with the primary non-fossiliferous, than with the succeeding formations, forming centres in gneiss and mica slate, and rising above them in magnificent pinnacles; it is therefore in the primary region that granitic mountains may be expected to predominate; of this we find an instance in the Grampian chain which stretches in a north-east and south-west direction, intersecting the country. The granite is most largely developed on the north-east side of. the country; it there commences about the parallel of Stonehaven, extends northward to Peterhead and Banff; and, in a westerly direction, along the courses of the Dee and the Bon; and still continues along the banks of the Tilt, Loch-Ericht, Loch-Lydoch, and terminates in this line near Oban and Fort-William; from the latter rises Ben-Nevis, composed of granitic sienite. But this is not the only range. Another may be traced commencing in the north between Thurso and Portskerry, which passes along, at irregular distances, near Loch-Baden, the neighbourhood of Dornoch, Loch-Oich, on the line of Loch-Ness, and terminates in a lofty mountain at the head of Loch-Sunart, on the west coast. Granite is found in several of. the Western Isles, as in Rum, and is magnificently displayed in the Isle of Arran; – Goatfell and the surrounding peaks are of granite. The granitic summits of these mountains form the highest land in Britain. Ben-Nevis is 4,373 feet above the level of the sea, and Ben-Macdui rises about 17 feet higher. Though the granitic formation covers a greater area, and rises to a greater altitude in the north than in the south of. Scotland, yet the latter is not deficient in this interesting, rock. It rises through the older greywacke (the Cumbrian system) in Dumfries-shire; occupies a great space in. New Galloway and in Kirkcudbright; and near Kirkmaiden, in the form of dykes. In some of those mountains, stones fit for the purposes of the jeweller have been found. The mountain Cairngorm, in Inverness-shire, has long been celebrated for its rock crystal, of a smoke-brown colour, and named Cairngorm from its locality, which, when cut by the lapidary, is highly esteemed for its colour and brilliancy, and is employed for seals, brooches, and other ornamental purposes. Topazes of a light blue colour, and sometimes of very large size, have occasionally been found on the same mountain, and also beryl (aqua marine), more rarely. Unstratified rocks of every other kind also prevail in Scotland; including all the varieties of Trap (commonly named whinstone), basalt, greenstone, compact feltspar, pitchstone, porphyries, and amygdaloids, which in many parts display ranges of symmetrical columns, sometimes of great extent – as at Arthur-Seat near Edinburgh, in several parts of the coast of Fife, in the islands of Eigg, Arran, Lamlash, and in the incomparable Staffa. But we shall attend to the distribution of these rocks throughout the country. They are connected with the older greywacke and red sandstones of the south of Scotland. Trap forms a great part of the Cheviots on the borders, and passes northwards into the districts of Dunse, Coldstream, Kelso, Melrose, Selkirk, and Roxburghshire, rising into beautiful dome-shaped hills. Hounam-Law, the. Eildons, and Ruberslaw (the last, near 1,500 feet high), may be cited as examples. But in the great central valley of Scotland, beginning at Montrose on the east coast, trap hills appear in patches in the old red sandstone, passing in an irregular line to the frith of Tay, from the south-eastern extremity of which they proceed in a south-westerly course, without interruption, but varying greatly in breadth, through Dunning, Kinross, and Stirling, to Dumbarton. Another line, but less continuous, commences about Cupar, near St. Andrews, along the coasts of Fifeshire, and appears in groups about Linlithgow, Bathgate, near Glasgow, onwards to Paisley, and thence to Greenock, where it is greatly expanded, and turns north to the banks of the Clyde, nearly opposite the Dumbarton range. A third parallel range, also in interrupted masses, commences at Dunbar, is continued in the Pentlands, Tintoc, and other hills in Lanarkshire, and in Ayrshire, about Kilmarnock, Ayr, and New Cumnock. In Galloway, trap is in some parts greatly expanded. A few of those localities may be mentioned, as we are not aware that any public notice has yet been given of its existence in those parts. A dyke of greenstone occurs near Kirkcolmpoint in greywacke, at the western extremity of Loch-Ryan; Cairn-Pat, between Stranraer and Port-Patrick, is also greenstone; and thence, the greywacke of the whole coast to the Mull of Galloway is intersected by dykes and hills of several varieties of trap. On the northern side of Loch- Ryan, it is seen involved amongst the roofing slates of the Cairn; and a range of trap hills extends thence, rising through the greywacke, flanking the edge of the loch, taking a south-easterly direction, passing by Castle-Kennedy to the north, and onwards to New-Luce. Here it expands to an enormous extent in every direction; to the south it approaches Glenluce-bay. At Knocky-bay, a short distance north of New-Luce, a lead mine was at one time worked, but becoming unproductive, was abandoned. It may, however, be observed, that the greatest development of trap is in the great central coal district, where it has fractured the strata, and raised the edges of the coal seams to the surface, an important natural operation, by which coal and its other useful accompaniments, ironstone, limestone, and building materials, have been made known and accessible. In the trap rocks of Scotland many interesting minerals are found. The far-famed Scotch agate or pebble, abounds in nodules included in trap, near Montrose, Perth, and other places; and many of the most beautiful of the zeolites are found among the hills around Dumbarton, the opposite side of the Clyde, and in many other localities.
“The coal-fields constitute the principal mineral treasures of Scotland. The great coal district extends across the island from the eastern corner, or, as the district is termed in Lowland Scotch, the ‘East Neuk’ of Fife, to the mouth of the Clyde in Dumbartonshire on the west, and into East-Lothian on the east. It is not, however, continuous throughout the whole distance, but consists rather of a succession of large detached coal-fields. Its superficial extent has been estimated at nearly 1,000 square miles; and it has also been calculated that, according to the present consumption, it may be worked with advantage during 3,000 years. The Fife coal-field, north of the Forth, extends from Stirling to St. Andrews, and is in some places 10 miles broad. The richest portion of it lies between Dysart and Alloa. The Lothian coal-field, on the south and east of Edinburgh, is about 25 miles in length, with a breadth of five or six, and covers an area of 80 square miles. To the westward of Edinburgh there is no coal for several miles; but at Bathgate, workable beds are found, which extend westward, with some interruptions, to the neighbourhood of Glasgow, forming the great coal-field of Lanarkshire. The Clyde and the Forth form the boundaries of this field; but beyond Blantyre, the coal extends on the south side of the Clyde to the Cathkin-hills. After passing Glasgow, the coal-field stretches westward from the south bank of the Clyde, and occupies the valley in the line of the Ardrossan canal, extending through Renfrewshire to Dalry in Ayrshire; the most southerly point being at Girvan. Several small fields occur at different parts of the south of Scotland, particularly at Sanquhar, in Dumfries-shire, and Canoby; in the same county, on the borders of England. Coal is found also at Brora in Sutherlandshire, and Campbelton in Cantyre, but in insignificant quantities. Besides the fossil fuel yielded by the coal-fields, ironstone of excellent quality abounds in many of them; and is smelted to a great amount, and manufactured into articles suited for every useful purpose, at the great works of Carron, Shotts, Cleland, Airdrie, Clyde, Wilsontown, Muirkirk, Glenbuck, and some other places. It is the abundance and cheapness of coal in its vicinity that has enabled Glasgow to rival Manchester as a manufacturing emporium. Next to coal and ironstone, the most valuable mineral product of Scotland is lead, of which there are rich mines at Leadhills and Wanlockhead, in the Lowther-hills, on the borders of Lanarkshire and Dumfries-shire. Lead is also procured at Dollar in Clackmannanshire, Strontian in Argyleshire, Belleville in Inverness-shire, and Leadlaw in Peebles-shire. A considerable quantity of silver is extracted from the lead. Particles of gold have frequently been found in the small streams among the Lowther-hills, and also immediately under the vegetable soil which covers the surface of the latter. Scotland abounds in quarries of the finest building materials, particularly sandstone, – hence the beauty of the numerous public edifices which adorn its cities and towns. The principal sandstone quarries are Craigleith, a little to the west of Edinburgh; Binnie, near Uphall, Linlithgowshire; Humbie, near South Queensferry, also in Linlithgowshire; Giffneugh, near Glasgow, Lanarkshire; Longannet, near Kincardine, Perthshire; and Milnefield or Kingoodie, near Longforgan, Perthshire. Roofing-slates, only inferior to those procured in Wales, are quarried extensively at Ballachulish, and in the island of Easdale, both in Argyleshire. Granite is brought from Aberdeen to pave the streets of London; and the granite of Kirkcudbright has been partly used in the construction of the Liverpool docks. Variegated or veined marble, of a beautiful appearance, is found in Sutherlandshire, at Glentilt in Perthshire, at Tyree in Argyleshire, at Muriston in West-Lothian, and in other places.”
Octohedral alum occurs at Hurlet near Paisley, at Creetown in Galloway, and in the vicinity of Moffat; rock-butter, at Hurlet; compact gypsum, in the Campsie-hills; fibrous gypsum, in Dumbartonshire, in the vicinity of Moffat, and on the banks of the Whitadder; foliated fluor, in various situations, but rarely, though abundant in England; conchoidal apatite, or asparagus stone, near Kincardine, in Ross-shire, and in the Shetland isles; common arragonite, or prismatic limestone, in the lead mines of Leadhills, and in secondary trap-rocks, in various situations; fibrous calc-cinter, the alabaster of the ancients, in Macallister’s-cave in Skye; slate-spar, imbedded in marble in Glen-Tilt, and in Assynt; common compact lucullite, or black marble, forms hills in Assynt; stinkstone, or swinestone, occurs in Kirkbean, and the vicinity of North-Berwick; white domolite occurs in beds containing tremolite, in Iona; brachytypous limestone, or rhomb-spar, near Newton-Stewart, and on the banks of Loch-Lomond; foliated brown-spar, in the lead mines of Leadhills and Wanlockhead; columnar brown-spar, on the banks of Loch-Lomond, and near Newton-Stewart; prismatic, or electric calamine, at Wanlockhead; pyramido-prismatic baryte, or strontianite, at Strontian in Argyleshire; foliated prismatoidal baryte, or celestine, at Inverness, and in the Calton-hill of Edinburgh; white lead-spar, and black lead-spar, at Leadhills; indurated, friable, and green earthy lead-spars, prismatic lead-spar, or sulphate of lead, and radiated prismatic blue malachite, or blue copper, at Leadhills and Wanlockhead; – fibrous common malachite, at Sandlodge, in the mainland of Shetland; – radiated cobalt-mica, or cobalt-bloom, at Alva in Stirlingshire, and in the limestone of the coal measures in Linlithgowshire; earthy blue iron, on the surface of peat-mosses in Shetland; scaly graphite, in Strath-Beauly in Inverness-shire, and in the coal formation near Cumnock; foliated chlorite, in Jura; earthy chlorite, along with common chlorite, at Forneth-cottage in Perthshire; other chlorites, variously, and in abundance; common talc, in Perthshire, Aberdeenshire, and Banffshire; indurated talc, or talc-slate, in Perthshire, Banffshire, and Shetland; steatite, or soapstone, in the limestone of Iona, and the trap-rocks of the Lothians, Arran, Skye, and some other places; – diatomous schiller-spar, in the serpentine of Fetlar, and Unst in Shetland, and of Portsoy in Banffshire, in the greenstone of Fifeshire, in the porphyritic rock of Calton-hill, and in the trap of Craig-Lochart, near Edinburgh; hemiprismatic schiller-spar, or bronzite, in Skye, and near Dimnadrochit in Inverness-shire: prismatoidal schiller-spar, or hypersthene, in Skye and Banffshire; kyanite, in primitive rocks at Boharm in Banffshire, and near Banchory in Aberdeenshire, and in mica-slate near Sandlodge in the mainland of Shetland; fibrous prehnite, in veins and cavities in the trap of Castle-rock, Salisbury-Crag, and Arthur-Seat, Edinburgh, of Bishopton and Hartfield in Renfrewshire, of Cockney-burn and Loch-Humphrey in Dumbartonshire, of the vicinity of Beith in Ayrshire, and of Berwickshire, Mull, and Raasay; rhomboidal zeolite, or chabasite, in crystals in the vesicular cavities of the Mull and Skye trap; mealy zeolite, or mesotype, near Tantallan-castle in Haddingtonshire, and in Mull, Skye, and Canna; pyramidal zeolite, or apophyllite, in the trap-rocks of Skye; some other species of zeolite, variously, and in abundance; adularia, a rare sub-species of prismatic felspar, in the granite of Arran; compact felspar, a more common sub-species, in the Pentland and the Ochil hills, in Tinto, and in Papa-Stour in Shetland; other sub-species of prismatic felspar, in numerous localities; sahlite, a sub-species of pyramido-prismatic augite, in Unst, Tiree, Harris, Glentilt, Glenelg, and Rannoch; asbestous tremolite, in Glentilt, Glenelg, Iona, Shetland, and other places; common tremolite, in Glentilt, Glenelg, and Shetland; rock-cork, a kind of asbestos, in veins in the serpentine of Portsoy, and in the red sandstone of Kincardineshire, in small quantities at Kildrummie in Aberdeenshire, and in plates in the lead veins of Leadhills and Wanlockhead; flexible asbestos, or amianthus, in the serpentine of Portsoy, Lewis, and Harris, of Mainland, Unst and Fetlar in Shetland, and in some other places; rigid or common asbestos, in the serpentine of Shetland, Long-Island, and Portsoy; epidote, or pistacite, in the syenite of Arran and the Shetland mainland, in the gneiss of Sutherland, in the trap of Mull and Skye, in the quartz of Iona and Rona, and in the porphyry of Glencoe, and other districts; common zoisite, in Shetland, Glenelg, and the banks of Loch-Lomond; common andalusite, in the primitive rocks of Aberdeenshire, Banffshire, and Shetland; – saussurite, between Ballantrae and Girvan; common topaz, in an alluvium in the granite and gneiss districts of Mar and Cairngorm; schorlous topaz, or schorlite, in Mar; beryl, along with topaz and rock-crystal, in an alluvium among the Cairngorm range; common amethyst, in greenstone and amygdaloid, in many localities; rock or mountain crystal – a variety of which is the Scottish Cairngorm stone – in the alluvium of the Cairngorm district, in druse cavities in the granite of Arran, and in various other geognostic and topographical positions; rose or milk quartz, in the primitive rocks of various districts; conchoidal hornstone, in the Pentland-hills; common calcedony, in most of the trap districts; carnelian, in most of the secondary trap districts, solitarily, or in agate; striped jasper, in the clay porphyry of the Pentland-hills; porcelain jasper, among pseudo-volcanic rocks in Fifeshire; agate jasper, in the agates of central Scotland; precious and common garnet, variously in primitive rocks; prismatic garnet, or cinnamon-stone, in gneiss near Kincardine in Ross-shire; prismatoidal garnet, or grenatite, in Aberdeenshire and Shetland; common zircon and hyacinth, in Galloway, Inverness-shire, Sutherland, Shetland, and other districts; – common sphene, or prismatic titanium-ore, in the syenite of Inverary and of Criffel, and other Galloway-hills, and in some other parts of Scotland; rutile, or prismato-pyramidal titanium-ore, in the granite of Cairngorm, and the quartz of Killin and Beniglo; prismatic wolfram, in the island of Rona; iron sand or granular magnetic iron-ore, in the trap-rocks of various districts; micaceous specular iron-ore, at Fitful-head in Shetland, in clay-slate near Dunkeld, and in the mica-slate of Benmore; red hematite, or fibrous red iron-ore, in veins in the secondary greenstone of Salisbury-Crags, and in the sandstone of Cumber-head in Lanarkshire; columnar red clay iron-ore, among other pseudo-volcanic productions in Fifeshire; pea-ore, or pisiform brown-clay iron-ore, in the secondary rocks of Galston; bog iron-ore, in various parts of the Highlands and Islands; scaly brown manganese-ore, near Sandlodge in Shetland; grey manganese-ore, near Aberdeen; – octahedral copper, in the serpentine of Yell, and the sandstone of Mainland in Shetland; – prismatic nickel pyrites, or copper-nickel, at Leadhills and Wanlockhead, and in the coal-field of Linlithgowshire; nickel ochre, in the same localities as the last, and at Alva; prismatic arsenic pyrites, at Alva; magnetic, or rhomboidal iron pyrites, in Criffel, Windyshoulder, and other Galloway hills; yellow, or pyramidal copper pyrites, near Tyndrum in Perthshire, and in the Mainland of Shetland; – grey copper, or tetrahedral copper-glance, at Sandlodge in Shetland, at Airth in Stirlingshire, at Fassney-burn in Haddingtonshire, and in the vicinity of Girvan; vitreous copper, or prismatic copper-glance, in Ayrshire, at Fassney-burn, and in Fair Isle; rhomboidal molybdena, in granite and syenite at Peterhead, in chlorite-slate in Glenelg, and in granite at the head of Loch-Creran; molybdena ochre, along with the last, at the head of Loch-Creran; grey antimony, or prismatoidal antimony-glance, in greywacke at Jamestown in Dumfries-shire, and among primitive rocks, accompanied by green fluor in Banffshire; – yellow zinc-blende, at Clifton near Tyndrum; brown zinc-blende, at Clifton, and in small veins with galena, in the Mid-Lothian coal-field; – amber, or yellow mineral resin, on the sea-beach; petroleum, or mineral oil, at St. Catherine’s well in the parish of Liberton, and in Orkney; asphaltum, or slaggy mineral pitch, in secondary limestone in Fifeshire, and in clay ironstone in Haddingtonshire; – indurated lithomarge, in nidular portions, occasionally in secondary trap and porphyry rocks; mountain soap, in secondary trap in Skye; chiastolite, in clay-slate near Balahulish in Argyleshire; iserine, in the sand of the Don and the Dee; pinite, in porphyry in Beniglo, and near Inverary.