I have recently lost one of my diamond stud earring. It is approximately 0.40 to 0.42 SI-1 D color (no cert.- only apprasial from vendor whom doesn't sell diamonds anymore, so I cannot get a replacment from him). I am in the process of getting it replace. What is the best method of getting it replaced? (i.e. - buying the diamond directly from the internet or going to the local malls). Thanks a million!!!