Featured Art Deco buttons, please help identify mark!

Hi,
I wonder if anyone can identify the mark of this buttons, I do not know what metal they are made of, tested for sterling silver and they are not sterling.
The mark is not legible, neither I can make out letters, neither pictorial something…
Thank you.
Kind regards,
Simona

 

I wonder if they are 1970s Art Deco revival.

 

Think you're right. Execution of both fronts and backs looks slightly out of Art Deco period.

Debora

 

That's what I thought.

 

Can you get a closer look at the mark for us?

A good way to tell proper Art Deco from the revivals is the decorative bead lines are rounded on the old stuff and more squarish (like a line that has had cuts made in-between the "beads") on the newer. The nineties ones are particularly chunky.

 

I will try to describe them the best I can…
They do not look to me chunky, however if I had another similar ones to compare, it would be probably be a more accurate description.
The black stone or whatever is in the middle started to wobble now, I probably kept them in water for too long, and most likely I wash them too much. The small pearl in the middle keeps the black stone in place. The marcasite look intact and the lines that separate them look square to me. The sides of the buttons are slightly rounded, not sharp when touched.
The mark at the back looks like a hexagon with another smaller hexagon inside it. Looking in the middle of the mark, it’s very difficult to distinguish if it’s a pictorial or letters, but I imagine that I can see letter L, 3 times.
Thank you for your help.
Xx