Summary

H. N. R. Journal of the Straits Branch of the Royal Asiatic Society (1891)

The form, however, of a stone are must always depend on the texture and hardness of the stone and its cleavage. And the exceedingly hard texture of this granite is, no doubt, the reason for its broad shape. The edge has evidently been ground very carefully, but not equally, one side being flatter than the other. From this I gather that the weapon was used as an adze or biliong.
Source: Wikisource

Get perspective with Kwize: daily news enlightened by great literature