Platinum diamond ring varieties differ in quality and purity. Hence, it is really crucial to inspect the quality of the metal as well as to deal with a credible jeweler before purchasing a platinum diamond band ring. One of the best ways to identify the quality and purity of a platinum diamond ring is to check the markings on the ring. There will be a marking on the inner band if the ring that indicates the quality of the platinum metal; a good platinum diamond band ring will be marked 0.95 plat. Note that you will have to use a magnifying glass in order to read these markings. Another option that you may consider to determine the quality for your platinum diamond band ring is to check the metal constitution of the ring. Usually, the platinum metal will be mixed with an alloy of other metals in order to enhance its hardness and durability. A platinum diamond ring with 90% or more platinum is considered as the best quality platinum rings. Apart from this, make sure that you are shopping at a credible jewelry store and the seller is able to give all the necessary information regarding your diamond.