Page:Journal of the Straits Branch of the Royal Asiatic Society (IA journalofstrait121878roya).pdf/49

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one meets this ore all over the country. It is frequently rich enough to show a metallic fracture and bears a close resemblance to the ironstones described by Horsfield es appearing in such profusion in the tin-mining districts of Bauka. I have never observed this ore, however, in Sarawak in the extensive veins and reticulations mentioned by him; but, if one may be allowed to form and opinion from the written descriptions only of Horsfield and Logan, these iron ores belong to the same class as the Ironstone of the former writer, and the Lateritic iron-ores of Logan's writings on the Malay Peninsula.

Copper Lead and Tin.—The first of these minerals has been detected in very unimportant traces in Upper Sarawak on the Dutch border; the two latter, though often reported, have not been discovered even in traces. Galena is said to have been obtained in the vicinity of Bidi, but I am not in a position to vouch for the accuracy of the report. Copper occurs in minute quantities in the form of green and blue carbonate in connection with the antimony lodges at Busan, but there is no evidence at present to lead us to suppose that any workable deposit of Copper ores will be discovered in Sarawak. As to Tin, on the contrary, there is reasonable ground for expecting that it will be found to exist; having regard to the close similarity in geological constitutions between certain parts of the Territory, and the richly-stanniferous localities of Banka and Malacca.

Antimony has long been known as the staple mineral export of Sarawak. It ores are distributed over the whole of the Territory as well as being found beyond the frontiers in Brunei and in Dutch Borneo; but they have not been ascertained to be in workable quantity in any part of the island except in the district of Upper Sarawak (Proper), where, however, all the more accessible deposits are exhausted.

The most productive localities worked have been the Busan veins, the Jambusan, Busan, and Piat surface ore and the Bidi lodes and surface ore. At all these places, with perhaps the exception of Bidi, the out-put has either ceased altogether, or has greatly decreased during the past three years, but a great deal of inferior ore is still turned out. Bearing in mind the history of the mining operations as Jambusan, a new find may yet be heard of even in the abandoned working—so easy is it in a country densely covered with jungle, like Borneo, to go on working for months aud years within a few yards of a valuable deposit which is revealed at length by mere accident. In addition to the above-mentioned localities, antimony has been marked