Like the title says, I seem to recall reading somewhere (Wikipedia) that during the christianization of Scandinavia, many of the defiant norfolk wore hammer shaped pendants which were symbolic of Thor's Hammer. How much of this is true?
It has been thought that they did but nothing was proven from an historical document perspective that they did. Recently, however, Mjolnir necklaces have been found that have been dated to that era, showing that they did at least exist and were worn, but that does not prove how abundant or common they were. When I find some of the sources regarding the artefact finds I will edit this post with the links.
I forgot to go back and find sources for you (per my previous post) but I just noticed this article, which may help a bit (translated into english for you):