About three daysʼ journey up the Pongole river lies the district of Songo, with a population of twenty-five thousand souls, Dayers, and a few Chinese, under a Malay and an independent prince. The population is chiefly employed on the rich mines of gold in the neighborhood, which is particularly pure and abundant; but the mines are not wrought with the same industry as those under Chinese management. The Dutch thought it of so much consequence as to keep a force at Songo, and to place the present rajah on that musnud. About two daysʼ journey farther up lies another gold district, called Santam, the inhabitants of which are principally Dayers. Beyond Santam, and higher up on the same river, lies the town of Sukadow, abounding in gold, the inhabitants of which are also Dayers.
Matan belongs to the rajah of that name: he had the title of Rajah of Sukadana, until driven out of the latter place by the Dutch, seventeen years ago. There are ten thousand Dayers in this district, and a few Chinese and Malays. The mines of gold are abundant, and capable of becoming highly productive, as well as the mines of iron and unwrought tin; but the sultan is much addicted to the use of opium, and hence neglects a valuable country, capable, under better management, of becoming the most valuable district on all Borneo.
About three daysʼ journey from Pontiana lies the celebrated mountain of Landa, which, after Golconda, is the most valuable diamond mine in the world. There are at least thirty thousand people, principally Dayers, employed on the mines and agriculture; it belongs to a Malay prince, raised to that musnud twenty-five years ago by the Dutch, through the agency of the present Sultan of Pontiana: here also much gold is produced; and much more might be had under proper management.
There is a very valuable gold mine in the north of Borneo, at a place called Tampasuk, situated in the district ceded to the English by the Sultan of Sulo; but having become the principal pirate port on the coast, the working of the mines has been discontinued.
The whole produce of the gold mines of Sukadana is said to be annually about twenty piculs, or a million of dollars, at twenty-five dollars a bunkal; but no calculation of this sort can possibly be correct. Living, as the Chinese do, under the rapacity of despotic and ferocious freebooters, who are actuated by no one principle of honor, justice, or good faith, it is their interest to conceal the riches they amass, not only to preserve themselves from the clutches of these tyrants, but as the most compact substance to transport to their native shores, to which they repair with the fruits of their industry, by the annual junks that arrive at Pontiana, leaving the mines to new settlers: from two to three hundred leave Pontiana every year.
The standard of Slakow gold at Pontiana is affixed at twenty-three Spanish dollars the bunkal, of two dollars weight. The Songo and Laurat is twenty-five dollars the said bunkal.
Not having had an opportunity to inspect any of the gold mines personally, I know not if the ores readily melt of themselves, or whether they require the aid of any fluxes before they yield the metal; but I believe the principal attention of the miners is directed to the rich veins of pure native gold, and that no operation is performed beyond that of pulverizing, and simple washing; all the gold about Pontiana being in dust, though some I have met with in Borneo Proper was run into bars. About Landa, where the diamonds are found, the whole of the stratum is observed to be a clay of a red burnt appearance, nearly to the same degree as that of burnt bricks, which gives to the rivers hereabouts a peculiar tinge. Whether this has been formed by the action of subterraneous fires, or is the effect of volcanoes or earthquakes, I cannot decide; the latter are said to be frequently felt at Pontiana and at Sambas; and the former are said to exist in the central mountains of Borneo.
From the slovenly manner in which the diamonds are sought for by the Dayers, they seldom collect them of a size exceeding three or four carats weight each. When rough, the Landa diamond has a white or yellow hue; but none are found of that inky and flinty tinge, so valuable in some of the Golconda diamonds. But that Landa does produce them of a very considerable size, the extensive and valuable specimens in Java, as well as the quantities annually sent to Batavia, will evince. The King of Matan is at this instant in possession of a diamond weighing 367 carats: the value of which, according to the old mode of calculation, would be (367 x 367 x 2 = 269,378l.) The Sultan of Pontiana says, however, that a much larger price was offered for it by the Dutch government of Java. He refused, it is said, twenty-five laks of dollars, two sloops of rice, fifty pieces of cannon, and a hundred muskets. Several from twenty to thirty carats have been dug up. At Mompava there are said to be very rich copper mines; but from want of population, a vigorous government, and scientific mineralogists, little is to be hoped from them at the present day. At Pulo Bongorong, near Borneo Proper, there is plenty of loadstone found.
About one degree north of Sambas there is a country called Sarāwak, belonging to the Rajah of Borneo Proper; there is a vast district abounding in tin, in veins as rich and as plentiful as those wrought on Banca: but they have been neglected for a series of years; they were partially wrought before those of the latter were discovered, in the beginning of the last century. The tyranny of that government, the want of hands, and the contiguity of rich and valuable gold-mines, have together caused their utter neglect; and there is little probability of more favorable results, except under a change of government, and a happier order of things.
In the Matan districts there is an extensive and most valuable iron-mine, producing pure metal without any admixture of ore: it is fully equal in quality to the best Swedish iron. They run it into shot, and much of it is exported; but the gold-mines in its vicinity, and the want of a proper government, are obstacles to its further productiveness and utility. At Maday, on the northeast coast of Borneo, in the province of Mangidara, there is a very rich mine of gold. Pasir and Coti, in the Straits of Macassar, produce considerable quantities of gold; and gold and diamonds are brought down by the river to Benjarmasing. I have, however, no accurate information on the subject, and can simply note the general fact.