Two identical aperiodic monotile earrings, featuring three interlocking copies of the "hat" pattern from "An aperiodic monotile" by Smith, Myers, Kaplan, and Goodman-Strauss. Enamel coloring (yellow, green, and blue) with antique silver plating. 15mm across with a butterfly stud. My design was manufactured by Made By Cooper, who say they "use hypoallergenic fixings and platings to ensure direct skin contact is not a problem." They don't specifically describe the materials as nickel-free or medical-grade, so these may not be appropriate for people with known metal sensitivity.