If you were confused with the metal choices though, the below guide on the best metal choices for flat diamond rings will come handy.       Platinum Ranking at the top of the list, platinum is the clear-cut go-to choice for diamond ring metals these days. It not only looks amazing on the fingers with its subtle shine and quaint appeal but also comes with added properties like being naturally hypoallergenic and very durable. Palladium This is sort of an alternative to platinum diamond rings, mainly because palladium is much affordable yet having a similar charm as that of platinum. Palladium metal is strong and durable too, and it does not tarnish or require any re-plating to be done. White Gold A flat diamond ring made of white gold will be a budget-friendly option, but the metal might require re-plating after a couple of years. Yet again, white gold produces a radiant shine that offers a perfect backdrop for the centerpiece diamond.