There are many mistakes that you as a consumer should avoid when buying a wide diamond ring or anything similar. Below are two of the most important ones to watch.       Overlooking the Lack of a Diamond Guarantee Normally, this should set off sort of all bells and sirens in your head. A diamond guarantee ensures continued customer service and satisfaction and going without it means you are giving up those things. A seller who refuses to guarantee your purchase is openly admitting his lack of trust in the buyer, which is not something to be put up with. Assuming Equal Quality in All Stones Any diamond jeweler who says, “All our diamonds carry the exact same quality,” is asking to have stayed away from. No two stones can be the same in this regard.