The disclosure relates to a platinum alloy comprising (a) 55 to 63 wt. % of platinum, (b) 2 to 10 wt. % of cobalt, and (c) 27 to 43 wt. % of copper. The disclosure further relates to a platinum alloy comprising (a) 70 to 79.5 wt. % of platinum, 2 to 10. wt. % of cobalt, and (c) 10.5 to 28 wt. % of copper. The platinum alloys have excellent mechanical and optical properties for use in the production of ornamental articles such as rings, necklaces, earrings, watch bands, watch bodies and other jewelry. The disclosure further relates to a method of preparing the platinum alloys and their use in the production of ornamental articles. Still further the disclosure relates to ornamental articles comprising the platinum alloy and a method of production thereof.