412 MINERAL0G1CAL DESCRIPTION OF THE ISLAND OF BANKA. 
In the specimens of granite which I collected from this hill, the 
mica is, upon the whole, very sparingly distributed, the fragments of 
quartz are of very different sizes, from that of the smallest grain, to 
crystals nearly an inch in leng th, the felspar is mixed with the other 
parts in large oblong or rhomboidal fragments which are mostly ea¬ 
sily separated, and in many portions occupy the greatest proportion 
of the mass. In some portions minute particles of schorl are barely 
perceptible, in some these are uniformly mixed with the substance 
of the stone, in others none are to he discovered. 
Between the foot of the hill Ganten and the Settlements at Main- 
p&ng I met with more large rocks near the road ; in some places 
several of them occurred together ; the descent hither from the cen¬ 
tral district is very gradual, and the highest top of the Gunung Gan¬ 
ten, the largest of the transverse ridge, cannot, according to my es¬ 
timate, much exceed 500 feet above the level of the sea. From the 
settlement, I proceeded about 2 miles, nearly in an eastern direction 
to the district of the mines. On this tract which is on an average 
less than 2 miles distant from the northern shore of the island, I met 
again numerous granite rocks, forming large groups and rising pre¬ 
cipitous many feet high, often with regular sides and sharp angles, 
resembling in a great measure irregular basalts. Through the dis¬ 
trict of the mines, these rocks were dispersed very abundantly. 
From the mines I proceeded, nearly in a northern direction to the 
stockade, which was lately established here for the security of the 
miners. It is built on the extremity of a point or promontory, at 
the foot of which, the river of Seka discharges itself into the sea 5 the 
spot is completely naked, and the rocks present themselves of their 
natural colour, which in the forests is not distinguishable on account 
of the mass with which they are enveloped. Not only the extremity 
of this point, is covered with large rocks, but they are seen to extend 
into the ocean as far as the eye can reach. Their torm is highly di¬ 
versified and they exhibit almost every possible variety in which gra¬ 
nite is produced: many rise with sharp peaks to an enormous height; 
others are low, large and rounded on the surface : The most are 
collected in groups, rising to a considerable height with more or less 
