Unique and One of a Kind. Harvey Avedon cufflinks signed with patent number 2920363. This patent number was used by Harvey Avedon in the 1950s. Guadalupe Poppy Jasper stones set in gold fill over metal alloy. Guadalupe poppy jasper is exceedingly rare. It is only found in one place on earth, the Almaden Quicksilver Mine near San Jose, California. The mine has been closed since the 1940s. Mr. Avedon liked using unique gem and mineral stones in his work, keeping much of it one of a kind. Toggle style cuff links are in excellent condition. Jasper specimen is top quality and makes every piece unique. 3/4" rounded square.