Help with Identifying German? Mark

Hello, please could anyone assist with the mark on these earrings please? The gold clips on the back are marked k18 but I can’t work out the maker? Mark is similar to that of
Theodor Fahrner.

Thank you!


Definitely not Theodor Fahrner.

https://www.tademagallery.com/jewellery/d/theodor-fahrner-jugendstil-brooch/206419