Can anyone help with this bracelet?

This belonged to my Great-Grandparents and I believe originates from the 1950s. It was kept in an envelope from "Hamilton & Co Private Ltd. Calcutta & New Delhi" although I am puzzling over what the material actually is!

I know that he managed a manganese mine out there and wondered if it could be manganese ore. It is difficult to tell from looking whether it is tarnished metal or stones, but when it catches the light it has quite a sparkle.

Any help would be gratefully received!

 

Shine a light through them,they look like garnets.

 

interesting stones...they look rather large......but wee need clearer pics..

 

I put a very bright light behind them and they are completely opaque. Here is a better picture:

 

They look like jet.

 

Could be Andradite/ Melanite Garnet,but the stones would need to be tested.

 

Thanks for the info! Where can I get the stones tested?

 

competent jeweler with a gemologist on staff.... good place to start..