Both metals are white and hypoallergenic, hence can be used in jewelry. Although Palladium costs half the price of platinum and resists scratching, platinum is still considered superior as it’s easier to work with casting and repairs.
Look for hallmark on your jewelry using jewelers’ loupe or magnifying glass. Usually it’s on inside of a band, on clasps of necklaces and bracelets and on the post of the earrings. Palladium is generally marked 950 PALL, 950 PALLADIUM and Platinum is marked 950 PLAT, 950 PLATINUM etc,
Palladium has a distinctly gray tone while platinum’s tone is slightly whiter and weighs less than a platinum ring in the same style. You can weigh on a jewelers’ or any scale that measures grams. To test, place a drop of iodine on a clean surface on the jewelry metal. Iodine will turn black on 950 Palladium and will remain colorless on 900 or 950 Platinum.