In this way an agate of a couple of inches diameter, and of average hardness, will be neatly divided in less than a quarter of an hour.
The two surfaces thus obtained are then inspected, and if the stone be judged worthy, the lapidary proceeds to polish either or both of them. There is always some difference between the two, a slice having been taken out of the pebble answering to the thickness of the wheel; hence the importance of using a delicate disk, especially for valuable agates.
To accomplish the polishing, the thin wheel of steel is now exchanged for a much thicker one of lead, which takes its place upon the spindle. It is no longer the edge, but the ribbed upper surface which is now to do the work; and to charge it for this, it is smeared over with rotten-stone dipped in water. This heavy wheel is then set spinning at a rapid rate, and the pebble is pressed flat upon it with great force; the heavier the hand the better. As it slidders about, the action of the rotten-stone, which is very fine in the grain, gives it by degrees a high polish. And this polish is durable, and will preserve the agate from the corroding effect of our atmosphere.
Less than the above will not dress a pebble for the cabinet. Occasionally, much more is needed. For a very fine jasper I have seen two or three polishing wheels employed, the last disk being always loaded with soft rotten-stone.
As to the expense, it will cost from sixpence to ninepence to cut a small pebble through; and to polish one surface, perhaps as much more. This is supposing that you take your specimens direct to a working lapidary. If, instead of doing so, you leave them at a jeweller’s shop with directions to get them done, you may expect to be charged fully twice as much. Nor is this so unreasonable as it sounds; for the man so deputed acts as your servant and will look to be paid for his trouble: he must have recourse to the lapidary, and you might at once have done so yourself.
To dress a large pebble, especially if a difficult stone in the grain, is a more costly affair. It demands many consecutive hours of labour and unremitting attention, and involves a perceptible outlay in diamond. Moreover, the weight of such a stone causes, by its vis inertiæ, a severe strain on the machinery, which then fares like an engine drawing a monster-train up the inclined plane. This wear and tear of the wheels is so serious a consideration in provincial towns, where the supply of “plant” is limited, that few lapidaries out of London will undertake, for any reasonable sum, to dress the agates and close-grained jaspers when they run large.
One of my jaspers, a Devonshire beauty, took eight hours of cutting and polishing in Clerkenwell; and even this was a trifle compared to some of which I have heard tell. Certain substances again are intrinsically teasing to the wheel. There is a class of jaspery flints which have a dodge or twist in their texture; the lapidary abhors these visitors, and will not meddle with them, if he knows it, without bargaining for extra pay.
I have a great pleasure in seeing fine pebbles of my own polished. You can stop the wheel every now and then, and watch how the stone gets on. When the chiaroscuro begins to come out on the coloured pattern, the effect is like that produced by holding some lively object before a mirror. The surface no longer appears flat; but you obtain aërial perspective, as in a good painting.
It were vain to deny that the lapidary’s acquaintance might in time prove an expensive amusement; for pebble-hunting is a hobby, and like all hobbies is liable to be over-ridden. But experience begets caution. For a score of stones which a tyro will leave on the board to be cut, a connoisseur will not venture above two or three.