Help with unknown hallmark

Hello, all. I’m new here, so I hope I’m doing this right! I recently ran across a piece (ring) with the hallmark BLK-BRD. I have searched the web. I saw it in the Indian Native Hallmarks page, also stating that the maker was unknown. I thought maybe one of the learned paople in this group might know the answer.

thank you,

Lloyd Pruitt

Do you have the piece? A picture might help, thanks.