Rock and mineral: consist of sediment of Tajam Fomation. Quartz sandstone inserts siltstone. Primary tin froth is present with quartz in fracture veins and tissues. This unit, according to Baharuddin and Sidarto (1995), is related to the Kelapakampit Formation and is Permo-Carboniferous. It is reported that REE found in alluvial ehich is weathered of these sediment.

Tajam mount is a mountain located on the island of Belitung , Indonesia and is the highest point on the island . Tajam mount has a height of 510 meters above sea level. Administratively the mountain which is the peak of the hills is located in Belitung Regency , Bangka Belitung Islands Province . Physically Tajam mount is a series of hills with four peaks with an altitude of 200-500 namely Tura Peak, Kuwak Peak (Tajambini), Sharp Peak (Tajamlaki) and Nibung Peak, surrounding a valley of horseshoe open to the west. The upstream river in this mountain is Cerucuk River and Buding River .