These are generally lampworked glass beads in iridescent metallic shades in two tones (the bead will appear to be that of two shades when looked at from different directions). Resin beads is often manufactured utilizing a silicone mold and epoxy resin. They can be built to imitate other resources, including https://spoilmevintage.co.za/2024/10/31/unlock-the-secret-to-stunning-styles-with-temus-yellow-beads-you-wont-believe-the-looks-you-can-create/