MINERALOGICAL DESCRIPTION OF THE ISLAND OF BANKA. 423 
was divided by a sharp cutting instrument: these streaks were not 
completely regular or uniform, some were horizontal, others had a 
gentle inclination, they indicated the approach of the stratum which 
next followed, consisting of larger quantities of the ore distributed 
through the coarser fragments of decomposed granite rocks, which 
from the appearance of the stones brought up by the last works con¬ 
tain, or are intersected by veins of Red-Iron-stone. The stratum 
on which the miners were now employed was considerably extensive, 
spreading in all directions round the mine. 
Among the substances which remained from former works near 
this pit I remarked : 
1. Large fragments of siliceous rock of the same kind with that 
described above, found at the mines of Sungie-Bulak. 
2. Kongtdy or white friable earth, remaining at the bottom of 
the stratum, near the termination of the tin-ore. 
3. Amygdaloids or Breccias these particularly attracted my no¬ 
tice : many of the masses had the constitution of the Red-Tron-stone ; 
others were aggregate. Although I had found numerous loose frag¬ 
ments of the common Red-stone on the road to these mines, an at¬ 
tentive search had discovered to me none in large or fixed rocks. 
The fragments which were collected here, shewed plainly that the 
miners in taking out the stratum containing the ore, had encounter¬ 
ed extensive veins: and they informed me that the blocks which T 
examined, and which were abundantly strewed over the surface, had 
been taken from some of the latest pits. 
They differed in appearance considerably from the Red-Iron-stone 
found in the environs of Jebus and Klabbet, The stone was much 
more compact and ponderous. The fracture had mostly a metallic 
lustre, varying in shades of colour but without the cellulosities above 
mentioned. 
It was generally covered with a yellow or red ochreous crust, and 
some portions were completely converted into a yellow or red ochre ; 
but particles of quartz were in all instances perceived on the solid 
massess or in the friable calx. Some of the smaller fragments, and 
those particularly taken from the aqueducts were more purely Bre c- 
