All Kristina Collection jewelry is hypoallergenic and nickel-free, safe for sensitive skin. Metal: a combination of memory wire and metal components, which are made from Tombac, a brass alloy containing copper and zinc. Each wire is cut and formed by hand and the pieces are then soldered together. Coating: bronze finish, which is a patina finish over copper. The jewelry features both Czech and German glass beads. These beads undergo many processing steps, including heating glass and pressing it into molds, cutting and polishing, and adding a frosted finish using a tumbler with sand and water.