Unfortunately, I found no examples of inscriptions on Rai Stones. Maybe doing that could ruin the legitimacy of the stone for a transaction lol.

For the African glass beads, it was more of a symbolic attachment depending on the type of the bead.

And surprisingly for silver, there is an amulet with some latin inscription was found in Germany.

Article 1: https://archaeologisches-museum-frankfurt.de/index.php/en/#:~:text=The%20inscription%20was%20deciphered%20thanks,the%20age%20of%20the%20find.

Article 2: https://www.archaeology.wiki/blog/2024/12/16/frankfurt-silver-inscription/#:~:text=At%20the%20Archaeological%20Museum%20in,and%20create%20a%203D%20model.