The markings on a platinum ring indicate its purity; it will either be marked iridplat or plat. Iridplat means the ring is 90 percent platinum and 10 percent iridium, while the plat marking means the ring is at least 95 percent platinum.
Platinum is a valuable and rare metal, making it a coveted choice for fine jewelry. The metal is also strong, which helps battle the wear and tear of everyday life, and its white shine adds a desirable aesthetic. Many times, diamonds and other precious jewels are set in the platinum; it is a common yet expensive choice for wedding and engagement rings.