Moreover, we know that there are many different clays occurring in our geological strata. We have the clays of the Lower Tertiary; the clay of the Wealden; and the Kimmeridge and Oxford clays, both of which belong to the Oolite. Also in these main divisions, sundry mineralogical varieties are comprised under a common name. But the great age of the granite formation renders it certain that from none of these clays could those sapphires have come (as to their base), which are born of the granite rock. Indeed, our existing beds of clay are more or less mingled with felspar, and felspar is one of the “silicates;” whereas the blue sapphire is pure alumina free from all admixture of silica.
However this may be, the great fields for gems are in India and the island of Ceylon, and in certain parts of the Russian dominions. No very valuable stones have as yet been obtained from Australia; although the vicinity of gold-mines has always been held to be prolific in at least one kind: the “mother of ruby” being a roseate substance embedded in the rock, and generally met with alongside of a vein of gold. The topazes are not equal to those from Saxony.
As to our own sea-girt Isle, it is surely as guiltless of indigenous gems, as of white elephants or birds of paradise. Had any such existed with us, they must long ere this have been brought to light and appeared in the market. We have bored the plain to two hundred fathoms’ depth: we have pierced the hillside in tunnels which extend for miles: geologists and antiquarians have delved and hammered and sifted: many curious fossils have turned up, and a world’s wealth in minerals, but never anything like a diamond or an oriental sapphire.
It is well that, to console us under such apparent poverty as to the gems, we possess the treasure an hundred-fold in other shapes, though derived from the same sources. Clay gives us no sapphires; but it floors our ponds and canals, furnishes our earthenware, and yields the bricks which have built the ribs of London. Carbon refuses to flash upon us in the rays of an indigenous “brilliant,” but it feeds our furnaces, propels our steamers and locomotives, and cheers a million of household hearths under the well-known form of Coal. And Iron is our national sceptre: it reddens here no jacinth or ruby; but it supplies us with spades and ploughshares, lays down thousands of miles of railway, and has made England the forge and workshop of the known world for giant engines and massive machinery.
If our wealth be less dazzling than that from Golconda or Peru, it is, we may hope, more durable; flowing to us through a healthier channel, by the honest labour and steady perseverance of the sons of the soil.
This is somewhat of a digression from the subject of Sea-side pebbles. But then, as was said, the magnificent crystals are their near kindred; and in society the custom is to bring in any great connections we may have, on the first fair opportunity: that once done, our respectability is supposed to be established.
[2] On the banks of Newfoundland, and to the south of the Cape of Good Hope, extraordinary exceptions occur to this rule; the sea being there agitated to a vast depth, perhaps as much as five hundred feet. But this is probably connected with the current of the great gulf-stream.