Minangkabau Keris??

[Athanase]

For me, the gold band is original. The work seems typically Minang because it is identical to what is observed on Mingangkabau bracelets.
But it seems indeed that there has been a repair of the Buntut, the black spot that we see on one of the two faces seems to be a weld repair.

For the stone, for me it lacks a touch of pink in the color for it to be ruby.
The auction house said garnet, but it can also be spinel or glass because I do not know if they really check the stone.