14k plat irid question

[bgray]

I just bought a piece of vintage jewelry marked Irid. Plat. 14K. The stones are single cut diamonds. There are no other markings and I am wondering what era those markings signify? I have personally never seen this marking/stamp before. Thanks in advance.

 

[bcavitt]

Probably the body of the jewelry is Platinum/iridium alloy and the heads the single cuts are mounted in are 14 karat white gold.