&2 DISTRIBUTION OF MINERALS IN SARAWAK 



at Grogo and Sikunyit; and it has been observed in traces 

 between Aliup and Gumbang, at Sirin in the Samarahan, in the 

 Sadong district, at Marup in the Batang Lupar, and in the 

 Intabai and Poi tributaries of the Rejang river, and one good 

 specimen of sulphide has come under my notice from the Kagan 

 districts of the Upper Rejang. 



These wide-spread traces cannot be referred to a single centre 

 of dispersion such as it might be supposed the Upper Sarawak 

 field would present. They point to the presence of one or more 

 undiscovered accumulations of antimony ore to the east of 

 Sarawak Proper, though whether within the boundaries or at a 

 short distance beyond, cannot now be said. In Kanowit the. 

 traces are tolerably abundant, but their great distance island 

 renders it vain to hope they will be followed up for many years 

 to come, if at all. 



The ores commonly worked are native antimony ; gray sul- 

 phide, and the " oxide" or " red ore" (oxy-sulphide) . Native 

 antimony occurs in the form of worn rounded pebbles in alluvial 

 flats in the immediate vicinity of the vein-bearing limestone, 

 and especially in the gullies and crevices so characteristic of this 

 rock which are always more or less filled with a debris of clay 

 and fragments of veinstone and ore. My brother — to whom I 

 was indebted for many of these notes — informed me that he 

 once observed native antimony forming part of a vein, and in 

 this single instance it was scattered throughout a small horizon-; 

 tal lode of the sulphide. The ore in this form is not found in 

 large quantities, but as it contains a minimum of impurities, ap- 

 proaching more nearly to regulut of antimony than any of the 

 other varieties, and therefore requiring* no preparation before 

 being exported, it is always secured where met with. The 

 Busan hills have proved the richest depository of this ore. 



The oxide, like the foregoing* ore, is generally obtained in 

 rolled fragments and pebbles which are often seen to be only 

 blocks of sulphide, partially oxidized, and preserving their origi- 

 nal lamellar structure. It is found in the same situations as the 

 native antimony, but in much larger quantities. It has been 

 hitherto exported in its rough state, and is the least valuable of 

 the ores of antimony owing to the difficulties it presents in re- 

 duction. The largest boulder of which I have heard weighed 

 some 8 cwt., but the fragments are almost invariably small, 

 weighing from a pound to thirty or forty pounds. The chief 

 supply has been obtained from Boan, Piat, and Paku localities 

 around the base of the Busan hills. 



