All I can say is in the very olden times people would make thier own "Pendants" from a sentimental coin,maybe one that grandma gave them etc......people had more sentiment back then and wanted to hold on to thier memories and that is all they had :(
Yes CherryChola1 , the hole looks to have been made by something square and in those days all the nails used for building had square shanks...very interesting!