After sending 10 different diamonds to grading labs in the United States and abroad, a Rapaport survey found opinions that differed by as much as three color grades.
The survey results were announced during the Rapaport certification conference at the JCK Las Vegas show on June 2.
The survey found that the American labs that received the diamonds—the Gemological Institute of America, the International Gemological Institute, and EGL USA—graded the gems “in the same ballpark,” said moderator Saville Stern, although EGL USA was a little softer on color than the other two.
However, diamonds sent to overseas labs—including EGL Israel and EGL Hong Kong—received different results than those provided by the American labs, and in some instances the grades were two to three colors higher. Antwerp’s HRD lab was also a “little softer than GIA,” Stern said.
Stern worried that all the different standards make the industry vulnerable from a consumer confidence standpoint.
“Are all the labs speaking the same language if someone’s E is someone else’s J?” Stern asked.
