Vintage cufflinks

My dad wore these at his wedding. The only marking I can see looks like a K on the back they look like they’re gold, plated, or gold filled. I’m not sure if it’s a diamond or a crystal in the center. With a star shape accent. There are an excellent condition for their age and ready to be worn by the next person. They measure shy of 1 inch in length in between a half inch and three quarter inch in width