This 16G 10mm heart should be purchased to be outward facing for the right or left ear (not reversable). The material is brass with rhodium plating and is is bendable to open and close. Note only ben open forward and backward to the gems to avoid breaking.
Because brass contains copper, it can oxidize with moisture or skin chemistry and leave a harmless greenish tint on the skin. It isn’t an allergic reaction, but it does make these pieces better suited for occasional or event wear rather than daily use.