Jade Gate. Robert Gunn Trilogy, #3

Robert Gunn, founder of the Mandarin-Gold trading company, had always been quick to seize new opportunities. That had been the making of his vast Far Eastern trading empire. And when the change from sail to steam in the world's shipping made coal as valuable as gold. Gunn saw his way to another fortune. Vessels on the Eastern seas needed local supplies of fuel - and the man who discovered coal in the East would command the whole area.
Enormous power for his country and himself. Gunn believed that Jade Gate Island, off Borneo, hid coal deposits, and there were others who shared his belief. In a land where life was cheap and the prize incalculable, the race for coal was likely to be a fight to the death ... To the powerful and arrogant Dr. Robert Gunn, life 'might be likened to a fierce race for enormous prizes'. No prize could be richer than the discovery of coal on Jade Gate Island - but then no race could be fiercer, more uncertain, or more violent....