CARNELIAN, which is our purest form of chalcedony, is undoubtedly a more beautiful stone than the agate. This is either milk-white or of a deep red. The latter tint is becoming scarce in Britain, having been much sought out for the manufacture of seals and ring-stones, but now that “sards” are so much in vogue, the real carnelian may get a respite and appear in force again, as salmon have sometimes been known to do in their native streams after falling off for many years.
The “sard” may be considered as the carnelian of the desert, or the “carnelian” as the sard of the seashore. Sards are plentiful in the east. Travellers, whose path lies over the waste plains and sandy reaches of Egypt or Lybia, should pick up any darkly-tinted pebble they may descry on the surface of the ground: it is probably a sard, perchance a valuable specimen. One day, in homely Brighton, stepping into a lapidary’s, I found upon his counter half-a-dozen unusual-looking stones already cut in two, and some of them polished. “These are not English,” said I, “where did you get them?” He told me, in reply, that a gentleman just arrived from Egypt had taken these stones out of the mouth of his carpet-bag and left them with him to be dressed. I examined them closely. As I had expected, on learning the locality, one was a blood-red sard, and two others were jaspers; a fourth was curiously mottled and ribbed with chalcedony. They had been obtained without any expense, and at no trouble beyond that of stooping to pick them up, and all four were very saleable articles in the trade.
The finest red carnelians are brought from the East, but they occur also in Silesia, and splendid specimens of a dark hue have been obtained from the sands of the Rhine.
In Scotland, on the beach of St. Andrew’s, I found a pretty variety, “eyed,” but it is scarce. I have since seen similar stones, which had been picked up at Cromer or at Aldborough.
The AQUAMARINE is sometimes met with on the sea-shore at Aberystwith in North Wales, and more rarely on our eastern coast. Of course it is a crystal, which has come down from the inland rocks, and has afterwards been rolled smooth by the action of the waves among other pebbles.
The base of all our English crystals is Silica, with an admixture of lime. Rock-crystal is the purest form of Silica. Common spar is a carbonate of lime. The black or grey flints, which are shed in myriads from many a chalk-cliff, are “Silex” much debased; some dark, viscous matter, such as bitumen, having united, I think chemically, with the clearer substance. Quartz are the small crystals of silica; a mass of these will vary in its configuration.
Cairngorum stones are rock-crystals from the mountain of that name, deeply impregnated with iron and aluminium. The claret-coloured ones, found on Ben M’Dhui, are our nearest approach to an amethyst, and some deep-red specimens remind us of the garnet.
As I propose here to speak only of our sea-shore pebbles, I shall not dwell upon the Scotch crystals, which are, moreover, familiar to almost everybody in the ornaments of tartan dresses. Neither shall I touch upon the fluor spars of Derbyshire, or the magnificent crystals found in the mines of Cornwall and Cumberland.
All these belong to crystallography, and I am persuaded that, in our productions of the seaside, a crystallizing process has been the exception and not the rule. I will only add to what is said above, that, as far as I know, amidst the great range of tints comprised in the different crystals from Scotland and from Ireland, there is no instance of the peach-colour or delicate pink, such as are picked up on some of the “moraines” on the Alps of Savoy.