www.925-1000.com

I am thinking these may be French based on rhe mark Mecan and the diamond lozenge
Thank you in advance!

The maker is Marcel ALBERT, of Paris, symbol an ant between MA. The mark was registered on 1st February 1925.

Note that this company specialised in findings and especially catches, so they were almost certainly not the makers of the earrings, just the clip.
You should find other marks on the wire of the earrings, though it's doubtful they'll be legible.