Bad pictures - What could it be?

I found this little pin. It about 1 inch. When I got it, it was just black. Based on the pattern, I think it could be Celtic. On the back are some makers marks: the first row starts with the letter G and the last row ends with a cursive H or it could be also a K. There seems to be also an anchor. The other marks are illegible.

Thanks for looking :)