Hello from Newfoundland Canada. My recently deceased father found this 2 inch (50mm) pendant in the sand at low tide in beach near my hometown of Port au Choix.
Based on the text with the U in place of v in middle of word dates it back to very old latin. Also after corresponding with the Vatican, they are unsure why the word Mundi has an O instead of U
The area where found has a rich history of french and Spanish fighting for fishing rights.
Sorry if translation is difficult but I use google chrome to translate and correspond.
Any information one can offer as to the origin and historical relevance to pendant will be greatly appreciated. Thank you very much for viewing.