SARAWAK MINERALS. — BY J. S. CEIKTE. 199 
Corundum. — Occasional small pebbles of this mineral 
are washed up during the search for Diamonds. 
Haematite. — A few small pockets of this ore have 
been found in Limestone in Upper Sarawak. 
Magnetite. — Occasionally found but never in any 
quantity. 
Laterite. — Under the term Laterite may be classed 
the majority of the Iron ore deposits of the country ; 
these are as a rule small and the percentage of metal 
very irregular. 
Native smelters produce a very high class Iron from 
some of these ores. 
Limonite. —Nodules of Limonitc are found in certain 
beds in the coal measures. 
Wad. —An Impure Manganese ore of very general 
distribution found in amorphous earthy masses and as 
incrustations and stains; many of the black and brown 
clays of the country owe their colours to this mineral. 
Psilomelane. — Another common Manganese ore. Near 
Lundu it is found in irregular bands traversing a series 
of altered shales. This is the only place in the country 
where any attempt has been made to exploit Manga¬ 
nese, the deposit however proved to be only a surface 
enrichment. 
Bauxite. — Occurs at Puak as small concretionary 
nodules in clays resulting from the decomposition of 
impure limestones. 
Senarmon tide. 
Valentinite. 
Cervantite. 
These three oxides of Antimony have all been found 
in Upper Sarawak. Senarmontite alone occurs in any 
quantity and is one of the ores exported. The clays 
round the Limestone hills near Busau afford the main 
supply of this oxide ; from these it is washed up in the 
form of grains and amorphous lumps. 
Carbonates. 
Calcite , Limestone, Marble. —Carbonate of Lime in a 
variety of forms is well represented in the country. 
Limestone seamed and veined with Calcite and some¬ 
times altered to marble, outcrops all over Upper Sara- 
