Jewellery is a form of personal adornment, manifesting itself as brooches, rings, necklaces, earrings, and bracelets. Jewellery may be made from any material, usually gemstones, precious metals, beads, or shells. Factors affecting the choice of materials include cultural differences and the availability of the materials. Jewellery may be appreciated because of its material properties, its patterns, or for meaningful symbols.