Feature
Gems & Gemology, Fall 1994, Vol. 30, No. 3
An Update on Filled Diamonds: Identification and Durability
Robert C. Kammerling, Shane F. McClure, Mary L. Johnson, John I. Koivula, Thomas M. Moses, Emmanuel Fritsch, and James E. Shigley
The increasing numbers of fracture-filled diamonds present a major challenge to the diamond industry, especially with regard to detection and durability of the treatment in routine jewelry manufacturing and wear. This report focuses on recent products from Yehuda/Diascience, Koss & Schecter Diamonds (Genesis II), and Clarity Enhanced Diamond House (a subsidiary of Goldman Oved Diamond Co.). Like the Yehuda treatment, the latter two processes were found to be effective in improving the appearance of most of the samples examined for this study. Treated diamonds from all three firms were damaged by direct heating and by repolishing facets intersected by filled breaks. Some stones were adversely affected by some standard cleaning procedures and wear conditions. Although the lead-based glass filling materials may be detected by X-radiography and EDXRF spectroscopy, as well as by certain internal features, we found flash effects to be the most distinctive characteristic of fracture filling—observed in all the treated diamonds examined from all three firms.
