Mark of a battle axe of hammer in square cartouche on jade earrings

[mkad]

I found these sterling clip-on jade earrings with a mark I can't identify, and I've been looking.
It looks like it's a hammer, or a mallet, or a battle axe in a diamond cartouche.
I'm assuming that it's American; the only hallmark is the 925, which could be a few other countries, but I can't find this symbol anywhere.








Thanks for any help you can give.

[Aguest]

It could be a "double-headed eagle" symbol which is a popular symbol in a few countries, I am thinking Austria or Germany would be my best guess. :::
The quality of the earrings seems good, which is nice, hopefully an answer could be discovered :::::