Part 20

In Cornwall, the most common opinion entertained by the miners, is, that crude and immature minerals nourish and feed the ores with which they are intermixed in the mines; and that the minerals themselves will, in process of time, be converted into ores productive of those metals to which they have the nearest affinity, and with which they are most closely intermingled. And a distinguished professor, who is familiar alike with geology, chemistry and mineralogy, after visiting the mining districts of California, has given it as his opinion, that gold is constantly being formed there, by some powerful agency of nature which is still and steadily at work. And as a somewhat kindred view, Mr. Price, in his mineralogy of Cornwall, thinks it is most reasonable to conclude, that metals were made and planted in veins, at, or very soon after, the creation of the world; but that, in common with all other matter, they are subject to a degree of fluctuation, approaching to, or receding from, their ultimate degree of perfection, either quicker or slower, as they are of greater or less solid and durable frame and constitution. He supposes in every metal a peculiar magnetism, and an approximation of particles of the same specific nature, by which its component principles are drawn and united together; more particularly the matters left by the decomposition of the waters passing through the contiguous earths or strata, and deposited in their proper nidus or receptacle, until, by the accretion of more or less of its homogeneous

## particles, the metallic vein may be denominated either rich or barren.

DIAMOND MINES.

The word _diamond_, is supposed to be a corruption of the word _adamant_, in allusion to the great hardness of this gem, which is the most valuable of all the precious stones. Diamonds were originally discovered in Bengal, and in the island of Borneo; and about the year 1720, were found in Brazil. They are found of all colors; and those which are colorless, or of some decided tint, are most esteemed, though the latter kind are very rare. Those which are slightly discolored are the least valuable.

The specific gravity of the diamond, is, to that of water, in the proportion of about three and a half to one. It is the hardest of all known substances, and can only be cut and polished by its own dust or powder. The art of splitting or cutting and polishing this gem, though probably of remote antiquity in Asia, was first introduced into Europe in 1486, by Louis Berghan, of Bruges, who accidentally discovered that by rubbing two diamonds together, their surfaces might be rendered smooth. And the fine powder which is rubbed off by such friction, serves to grind and polish them. The diamond is of the nature of _charcoal_, or pure carbon, and is combustible: under the blow-pipe it burns away in a blue, lambent flame.

The high value attached to diamonds does not depend so much on their beauty and hardness, as on their great scarcity, and the labor and expense necessary in procuring them. Hitherto they have been observed only in the torrid zone; and Brazil is the only part of America in which they have been found. The historical account of their discovery in that country is as follows. Near the capital of the territory of Serro do Frio flows the river Milho Verde, where it was the custom to dig for gold, or rather to extract it from the alluvial soil. The miners, during their search for gold, found several diamonds, which they were induced to lay aside in consequence of their particular shape and great beauty, although they were ignorant of their intrinsic value.

The diamond works on the river Jigitonhonha are described by Mr. Mawe as the most important in the Brazilian territory. The river, in depth from three to nine feet, is intersected by a canal, beneath the head of which it is stopped by an embankment of several thousand bags of sand, its deeper parts being laid dry by chain-pumps. The mud is now washed away, and the =cascalhao=, or earth which contains the diamonds, dug up, and removed to a convenient place for washing. The process, which is as follows, is seen in the cut on the next page. A shed, consisting of upright posts which support a thatched roof, is erected in the form of a parallelogram, in length about ninety feet, and in width forty-five. Down the middle of its area a current of water is conveyed through a canal covered with strong planks, on which the earth is laid to the thickness of two or three feet. On the other side of the area is a flooring of planks, from twelve to fifteen feet in length, imbedded in clay, extending the whole length of the shed, and having a gentle slope from the canal. This flooring is divided into about twenty compartments, or troughs, each about three feet wide, by means of planks placed on their edges; and the upper ends of these troughs communicate with the canal, being so formed that water is admitted into them between two planks about an inch separate from each other. Through this opening the current falls about six inches into the trough, and may be directed to any part of it, or stopped at pleasure, by means of a small quantity of clay. Along the lower ends of the troughs a small channel is dug, to carry off the water.

[Illustration: DIAMOND WASHING IN BRAZIL.]

On the heap of earth, at equal distances, three high chairs are placed for the overseers, who are no sooner seated than the negroes enter the troughs, each provided with a rake of a peculiar form, and having a short handle, with which he rakes into the trough from fifty to eighty pounds’ weight of the earth. The water being then allowed to pass in by degrees, the earth is spread abroad, and continually raked up to the head of the trough, so as to be kept in constant motion. This operation is continued for a quarter of an hour, when the water begins to run clearer; and, the earthy particles having been washed away, the gravel-like matter is raked up to the end of the trough. At length the current flowing quite clear, the largest stones are thrown out, and afterward those of an inferior size; the whole is then examined with great care for diamonds. When a negro finds one, he instantly stands upright, and claps his hands; he then extends them, holding the gem between the fore-finger and the thumb. An overseer receives it from him, and deposits it in a bowl, suspended from the center of the structure, and half filled with water. In this vessel all the diamonds found in the course of the day are deposited, and at the close of the work are taken out and delivered to the principal overseer, who, after they have been weighed, registers the particulars in a book kept for that purpose.

When a negro is so fortunate as to find a diamond of the weight of seventeen carats and a half, the following ceremony takes place: he is crowned with a wreath of flowers, and carried in procession to the administrator, who gives him his freedom by paying his owner for it. He also receives a present of new clothes, and is permitted to work on his own account. For small stones proportionate premiums are given; while many precautions are taken to prevent the negroes from stealing the diamonds, with which view they are frequently changed by the overseers, lest these precious gems should be concealed in the corners of the troughs. When a negro is suspected of swallowing a diamond, he is confined in a solitary apartment, and means taken to bring the gem to light.

In the East Indies, the kingdom of Golconda, extending two hundred and sixty miles along the bay of Bengal, and having a breadth of two hundred miles from east to west, abounds in diamond mines. They are chiefly in the vicinity of the rocky hills and mountains which intersect the country, and in the whole of which diamonds are supposed to be contained. In several of the mines they are found scattered in the earth, within two or three fathoms of the surface, and in others are met with in a mineral substance in the body of the rocks, forty or fifty fathoms deep. The laborers having dug five or six feet into the rock, soften the stone by fire, and proceed till they find the vein, which often runs two or three furlongs under the rock. The earth being brought out and carefully searched, affords stones of various shapes, and of a good water. This earth is of a yellowish, and sometimes of a reddish color, frequently adhering to the diamond with so strong a crust that the separation becomes difficult.

To find the diamonds, the workmen form a cistern of a kind of clay, with a small vent on one side, a little above the bottom; in this vent they place a plug, and throwing into the cistern the earth they have dug, pour in water to dissolve it. They then break the clods, and stir the wet earth in the cistern, allowing the lighter part to be carried off in the form of mud, when the vent-hole is opened to let out the water. They thus continue washing, until what remains in the cistern is pretty clean; and then, in the middle of the day, when the sun shines bright, carefully look over all the sand, at which practice they are so expert, that the smallest stone can not escape them. The brightness of the sun being reflected by the diamonds, aids them in their research, which would be foiled if a cloud were to intervene.

The largest known diamond was found in Brazil, and belongs to the king of Portugal. It weighs sixteen hundred and eighty carats; and, although uncut, it is valued at the enormous sum of two hundred and twenty-four millions sterling, which gives an estimate of nearly eighty pounds sterling for each carat, the multiplicand of the square of its whole weight being taken. The one next in magnitude and value, is probably that mentioned by Tavernier, in possession of the Great Mogul. It was found in Golconda in 1550; is of the size of half a hen’s egg, and is said to weigh nine hundred carats. This diamond is the same as the famous “_Koh-i-noor_,” or “Mountain of Light,” now belonging to the queen of England, and which attracted so much attention in the great exhibition at London, in 1851. The one supposed to be next in value, is that belonging to the crown jewels of Russia, which weighs seven hundred and seventy-nine carats, and has been estimated at five millions sterling. But perhaps the most perfect and beautiful diamond hitherto found, is the one known as the Pitt diamond, which was brought from India by a gentleman of that name, who sold it to the Duke of Orleans for one hundred thousand pounds sterling. It was worn by Bonaparte in the hilt of his sword. It weighs about one hundred and thirty-six carats, or five hundred and forty-four grains. It ought, however, to be observed, that these estimates, founded on the magnitude and brilliancy of the gems, are very different from the prices which the most princely fortunes can afford to pay for them. The Russian diamond cost about one hundred and thirty five thousand pounds sterling; and the one called the Pitt or Regent, although it weighed one hundred and thirty-six carats only, was, on account of its greater brilliancy, purchased of a Greek merchant, for one hundred thousand pounds sterling. Several other large diamonds are preserved in the cabinets of the sovereigns and princes of Europe.

Why such immense value should be attached to diamonds, in all civilized countries, and by a kind of common consent, is one of those singular things that seem inexplicable. That a magnificent house, with a large estate, and the means of living not only in comfort but splendor, should be set in competition with, and even deemed inadequate to the purchase of, a transparent crystallized stone, not half the size of a hen’s egg, seems almost a kind of insanity! If for the mere consciousness of possessing a diamond of less than the weight of an ounce, any private gentleman were to pay four hundred and fifty thousand dollars in ready money, and an annuity of twenty thousand dollars besides, he would probably be thought beside himself. And yet not only was the above sum given, but a patent of nobility into the bargain, by the empress Catharine, of Russia, for the famous diamond “Nadir Shah.” In this case, however, though the seller acquired much, the purchaser did not suffer any personal privation; and in reality, notwithstanding the costliness and high estimation of diamonds, they are not put in competition with the substantial comforts and conveniences of life. Among ornaments and luxuries, however, they unquestionably occupy, and have ever occupied, the highest rank. Even Fashion, proverbially capricious as she is, has remained steady in this, one of her earliest attachments, during probably three or four thousand years. There must be, therefore, in the nature of things, some adequate reason for this universal consent; which becomes a curious object of inquiry.

The utility of the diamond, great as it is in some respects, enters for little or nothing into the calculation of its price; at least all that portion of its value which constitutes the difference between the cost of an entire diamond and an equal weight of diamond powder, must be attributed to other causes.

The beauty of this gem, depending on its unrivaled luster, is, no doubt, the circumstance which originally brought it into notice, and still continues to uphold it in the public estimation; and certainly, notwithstanding the smallness of its bulk, there is not any substance, natural or artificial, which can sustain any comparison with it in this respect. The vivid and various refractions of the opal, the refreshing tints of the emerald, the singular and beautiful light which streams from the six-rayed star of the girasol, the various colors, combined with high luster, which distinguish the ruby, the sapphire, and the topaz, beautiful as they are on a near inspection, are almost entirely lost to a distant beholder; whereas the diamond, without any essential color of its own, imbibes the pure solar ray, and then reflects it, either with undiminished intensity, too white and too vivid to be sustained for more than an instant by the most insensible eye, or decomposed by refraction into those prismatic colors, which paint the rainbow, and the morning and evening clouds, combined with a brilliancy which hardly yields to that of the meridian sun. Other gems, inserted into rings and bracelets, are best seen by the wearer; and if they attract the notice of the bystanders, divide their attention, and withdraw those regards which ought to be concentered on the person, to the merely accessory ornaments. The diamond, on the contrary, whether blazing on the crown of state, or diffusing its starry radiance from the breast of titled merit, or “in courts of feasts and high solemnities,” wreathing itself with the hair, illustrating the shape and color of the neck, and entering ambitiously into contest with the lively luster of those eyes that “rain influence” on all beholders, blends harmoniously with the general effect, and proclaims to the most distant ring of the surrounding crowd, the person of the monarch, of the knight, or of the beauty.

Another circumstance tending to enhance the value of the diamond is, that although small stones are sufficiently abundant to be within the reach of moderate expenditure, and therefore afford, to all those who are in easy circumstances an opportunity to acquire a taste for diamonds, yet those of a larger size are, and ever have been, rather rare; and of those which are celebrated for their size and beauty, the whole number, at least in Europe, scarcely amounts to half a dozen, all of them being in possession of sovereign princes. Hence, the acquisition even of a moderately large diamond, is what mere money can not always command; and many are the favors, both political and of other kinds, for which a diamond of a large size, or of uncommon beauty, may be offered as a compensation, where its commercial price, in money, neither can be tendered, nor would be received. In many circumstances also, it is a matter of no small importance for a person to have a considerable part of his property in the most portable form possible; and in this respect what is there that can be compared to diamonds, which possess the portability, without the risk of bills of exchange? It may further be remarked, in favor of this species of property, that it is but little liable to fluctuation, and has gone on pretty regularly increasing in value, insomuch that the price of stones of good quality is considerably higher than it was some years ago.

The art of cutting and polishing diamonds, has a twofold object; first, to divide the natural surface of the stone in a symmetrical manner by means of highly polished polygonal planes, and thus to bring out, to the best advantage, the wonderful refulgence of this beautiful gem; and, secondly, by cutting out such flaws as may happen to be near the surface, to remove those blemishes which materially detract from its beauty, and consequently from its value. The removal of such flaws is a matter of great importance; for, owing to the form in which the diamond is cut, and its high degree of refrangibility, the smallest fault is magnified, and becomes obtrusively visible to all. For this reason, also, it is by no means an easy matter, at all times, to ascertain whether a flaw is or is not superficial; and a person with a correct and well-practiced eye, may often purchase to great advantage, stones which appear to be flawed quite through, but which are in fact only superficially blemished.

Before leaving the subject of diamonds, it may be well to notice some other valuable stones that are much sought and prized for ornament. One of these is the _oriental ruby_. This, in its most esteemed color, is pure carmine, or a blood-red of considerable intensity, forming, when well polished, a blaze of the most exquisite and unrivaled tint. It is, however, more or less pale, and mixed with blue in various proportions; and hence it occurs rose-red, and reddish-white, crimson, peach-blossom red, and lilac-blue, the latter variety being named the _oriental amethyst_. It is a native of Pegu, and is said to be found in the sand of certain streams near the capital of the country; and it also occurs, with the sapphire, in the sands of the rivers of Ceylon. A ruby which is perfect both in color and transparency, is much less common than a good diamond; and when of the weight of three or four carats, is even more valuable than a diamond of the same size. The king of Pegu, and the monarchs of Asia and Siam, monopolize the finest rubies, in the same way as the sovereigns of India make a monopoly of diamonds. The finest ruby in the world is in possession of the first of these kings. Its purity has passed into a proverb, and its worth, when compared with gold, is inestimable. The dubah of Deccan, also, possesses a remarkably fine one, which is a full inch in diameter. The princes of Europe can not boast of any rubies of first-rate magnitude.

The _oriental sapphire_ ranks next in value to the ruby. When it is perfect, its color is a clear and bright Prussian blue, united to a high degree of transparency. The _astoria_ or _star-stone_, is a remarkable variety of this beautiful gem: it is semi-transparent, with a reddish purple tinge. And beside these, there are the _red_ sapphire, often called the oriental ruby, and the _yellow_ sapphire, which is called the oriental topaz. And in addition to these precious stones, or gems, there are also the _emerald_, of a beautiful green color; the _topaz_, which is of a yellow or light wine-color, and which by being heated, sometimes becomes rose-red, so as to be passed off as a ruby; the _jasper_ and _chalcedony_, which are of various colors; the _onyx_, which is a regularly banded agate, much prized for cameos, especially where the colors are very distinct and different; the _cornelian_, which is properly a red or flesh-colored chalcedony, much valued for seal-stones, &c.; and the _blood-stone_, or _heliotrope_, which is deep green, and somewhat translucent, and variegated by blood-red spots: all of which are much used in the various departments of jewelry.

We have reserved for this place, a notice of the hot-well at Clifton, England, which would have been mentioned in connection with the Geysers and other hot springs, but from its connection with the beautiful crystals known as _Bristol stones_ or _diamonds_, some of which are so hard as to cut glass, and are exceedingly clear, colorless and brilliant. When set in rings, in their natural state, these stones often appear of as high a polish and luster, as if they had been wrought by the most skillful lapidary.

The warm spring, or fountain, in the vicinity of which they are found, is called the _hot-well_. It is in the parish of Clifton, and is so copious as to discharge sixty gallons of water in a minute. It rises forcibly from an opening in the solid rock, at about twenty-six feet below high-water mark. On its immediate influx from the rock, the water is much warmer than when it is pumped up for drinking, for it is raised by pumps some thirty feet. Its qualities in a medicinal point of view are supposed to be valuable; but it is not on this point that we propose to dwell, and therefore we pass on to the rocks in the neighborhood, near which the _Bristol stones_ are found. Just below the hot-well, there rises a noble range of hills, which are not more remarkable for their hight, than for their being equally so on both sides the river, the strata in some places answering on each side for about a mile and a half in a serpentine course. These constitute one of the greatest natural curiosities in England. The rock beyond the hot-well, and on the same side, is named St. Vincent’s, a chapel dedicated to that saint having been formerly built on its summit. It is in hight three hundred feet, and has a majestic appearance. It supplies the naturalist with many curious fossils, the botanist with a variety of scarce plants, the antiquary with the remains of a Roman camp, and the less curious inquirer with a view of a most dreadful and surprising precipice.

The rocks in general, when broken up, are of a dusky red, brown or chocolate colored marble, very hard and close-grained, and which, on being struck with a hammer, emit a strong sulphureous smell. It will bear a polish equal to any foreign marble; and, when sawed into slabs and polished, appears beautifully variegated with veins of white, bluish-gray, or yellow. It is often employed for chimney-pieces; but it is principally used for making lime, for which purpose there is no stone in England so well calculated, nor is there any lime so strong, fine, and white, which excellent qualities occasion great demand for foreign consumption.