Notes on the distribution of the useful minerals in Sarawak
A.H. Everett, Resident of Bintulu, published this systematic survey of Sarawak’s mineral resources in 1878, the first volume of the Journal of the Straits Branch of the Royal Asiatic Society. Writing from direct field experience in the territory, Everett argues that while Sarawak’s mineral wealth has long been overstated by European imagination, the territory possesses genuine—if modest—deposits of antimony, cinnabar, gold, and coal, with the coal fields of the northwest coast representing the most promising future asset.
Summary
Everett opens by situating Sarawak within the broader geological context of the northwest coast of Borneo, describing the stratigraphic sequence of Upper Sarawak Proper: an ancient blue limestone (possibly Paleozoic) overlain unconformably by sandstones, conglomerates, and clay-shales, with intrusive igneous rocks—porphyrite, basalt, and greenstones—piercing both formations. He identifies the igneous intrusions as the key to the district’s mineralization, arguing that the antimony, arsenic, and cinnabar deposits occupy fissures caused by volcanic eruption and were deposited after the cessation of volcanic action, yielding a “remarkably recent date” for the mineral lodes (p. 14). He then enumerates the minerals found in each administrative district, noting that Sarawak Proper exhibits the widest range, including gold, antimony, arsenic, argentiferous arsenic, cinnabar, cobalt, nickel, manganese, copper, iron, diamond, aquamarine, and coal (p. 14).
The bulk of the article is devoted to antimony, the territory’s staple mineral export. Everett describes the ore types—native antimony, grey sulphide, and oxide (oxy-sulphide)—their modes of occurrence in limestone fissures, and the principal workings at Busan, Jambusan, Piat, and Bidi. He reports that the most accessible deposits were becoming exhausted, with output declining over the preceding three years, though traces of antimony were noted as far afield as the Rejang and Batang Lupar districts, suggesting undiscovered accumulations to the east (pp. 20–23). On cinnabar, he details the Tagora hill deposit on the Staat river, discovered by Messrs. Helms and Walters of the Borneo Company, and a smaller, poorer deposit at Gunong Gading, attributing both to sublimation of heated vapours bearing quicksilver and sulphur (pp. 24–25).
On coal, Everett reports that the Lingga seams in the Batang Lupar district had been re-opened by the Government and were supplying fair steam coal, while the Mukah and Rejang outcrops, though of good quality, were too inaccessible for immediate exploitation. He transcribes Dr. Stenhouse’s analyses showing the Lingga coal to be nearly identical in carbon and hydrogen content to the Hartley-Newcastle coals, and notes successful sea-trials aboard the P&O vessels Delhi and Baroda (pp. 26–27).
Key Findings
- Antimony ore output peaked at 1,788 tons valued at $86,926 in 1872, but the most accessible deposits at Busan, Jambusan, and Piat were being exhausted, with the Ahup ore (80% pure sulphide) representing an exceptional high-grade find (pp. 20–22, 29).
- A ton of argentiferous arsenic ore from Bidi yielded only 5 oz. 16 dwt. 8 gr. of silver and 1 oz. 11 dwt. 4 gr. of gold, rendering extraction unprofitable (p. 19).
- Gold prices varied by locality: Marup gold fetched $32–$34 per bongkal, Paku $28, and Sadong $26, the difference reflecting silver content in natural alloy; no scientific analysis of Sarawak gold had been conducted (p. 17).
- Dr. Stenhouse’s analysis showed Sarawak Lingga coal at 81.41% carbon and 5.47% hydrogen, closely matching the Hartley Main seam (81.85% carbon, 5.29% hydrogen), while the cannel coal variant contained only 1.20% ash (p. 26).
- Cinnabar at Tagora was found deposited irregularly in strains, pockets, and strings within semi-metamorphic argillaceous shales at roughly 800 feet elevation, with the richest yields coming from alluvial washing of felspathic clays rather than vein-mining (pp. 24–25).
- The Borneo Company held a monopoly over all minerals in Sarawak except coal, gold, and precious stones, yet had never instituted systematic prospecting beyond Sarawak Proper, a failure Everett criticizes as counterproductive (p. 28).
Conclusion
Everett’s definitive assessment is that Sarawak “cannot be looked upon as a mineral-producing country” in the present, with antimony and cinnabar the only ores ever explored on a large scale, both now in decline or capricious yield (p. 27). He nonetheless anticipates future discoveries of antimony, cinnabar, and possibly tin and lead based on geological analogies with Banka and the Malay Peninsula, but identifies the coal fields of the northwest coast as the territory’s most significant potential asset, whose proximity to Singapore would “invest with a new interest this country” if developed on a commercial scale (p. 28).
Context
- The article was published in the inaugural volume of the JSBRAS, reflecting the Society’s early commitment to documenting the natural history and resources of the Straits Settlements and adjacent territories under British influence.
- Everett’s data on the Borneo Company’s mineral monopoly and its failure to prospect beyond Sarawak Proper provides a contemporary critique of the company’s extractive governance model in the White Rajah’s territory.