The 4C's describe the natural diamonds characteristics, These are Carat (size), Color, Clarity and Cut and are the industry grade standards from the Gemological Institute of America (GIA). Every diamond is specifically graded on this criterion. We go beyond the 4's when selecting diamonds to offer our customers. All our diamonds are GIA certified and do not generally use any other lab to grade our natural diamonds. We also see eye clean diamonds that do not have any BGM (Blue Grey undertones or Milky opaqueness) Additionally we only recommend non to slight flourescence. By only sourcing our diamonds from the most respected diamond suppliers we can assure you will receive a high quality diamond.