Vintage Lapis Lazuli Large on sale 1" Square Cufflinks (D3)

These cuff links are part of my mom's estate. I believe these were my grandfather's and are therefore vintage. They feature what appears to be a lapis lazuli stone that on sale has been etched with a geometric pattern. The stones have hints of gold flecks in them. I believe the metal is brass and as shown in the last photo there is some minor corrosion of the brass on the back of one of the cuff links (the other one is fine). These show signs of normal wear considering their age. These are large squares 1 inch x 1 inch. Super cool and original. I hope another wonderful man (like my grandfather) finds these and puts them to good use.