One of the types of diamond Enhancements, or treatments, to make them look better than they did in the ground. Pioneered by Yehuda of Israel, this is not necessarily a permanent treatment, since high heat from a jeweler’s torch can damage the inserted material, and therefore is not my favorite choice for an engagement ring. Sometimes the filling material can expand in a large fracture, shattering the diamond more. I do not recommend this treatment in an engagement ring, because the future possibilities could bring big disappointment to each of you.

According to Wikipedia:

“This process, which involves the use of specially-formulated solutions with a refractive index approximating that of diamond, was pioneered by Zvi Yehuda f Ramat-Gan, Israel. Yehuda is now used as a brand name applied to diamonds treated in this manner. Koss & Schechter, another Israel-based firm, attempted to modify Yehuda’s process in the 1990s by using halogen-based glasses, but this was unsuccessful. The details behind the Yehuda process have been kept secret, but the filler used is reported to be lead oxychloride glass which has a fairly low melting point. The New York-based Dialase also treats diamonds via a Yehuda-based process, which is believed to use lead-bismuth-oxychloride glass, but research into creating better, more durable, less traceable solutions is still being done, creating more silicone based solutions for the fracture filling process.”

WP Glossary Term Usage