Just did the CGA exam for recertification. One question was "Glass filled diamonds can be damaged by": correct answer a jeweler's torch. But... another possible answer is "ammonia-based jewelry cleaners" and that is counted as incorrect. We sell yehuda fracture-filled diamonds and Yehuda tells us that ammonia based cleaners can harm the filler. They recommend a soft brush and soapy water... We have carried them for years but were only informed about ammonia about a year ago. Also, rhodium plating solution might possibly damage the filler as will the pickle, of course. Still learning.
Joined: Thu Jan 24, 2008 4:01 pm Posts: 1902 Location: Pine City, NY and Dothan, AL
I don't think the Yehuda treatment is glass. From Wikipedia: "This process, which involves the use of specially-formulated solutions with a refractive index approximating that of diamond, was pioneered by Zvi Yehuda of Ramat Gan, Israel."
Glass can be affected by high concentrations of alkali, but ammonia, a weak alkali, is commonly used for cleaning glass, either by itself or as a component of commercial cleaners.
Specifically see Gems & Gemology fall 1994 Vol XXX, page 142. Refering to the Yehuda proceedure "...briefly stated this technique proceeds as follows: the diamonds are first cleaned then filled with molten glass at high temperature..." Also see Gems & Gemology Summer 1989, page 79. "...therefore this particular material is undoubtedly a lead-containing glass-like material". The complete articles are interesting. We carried Oved filled diamonds...basically the same filling technique, perhaps a slightly different formula.
Joined: Sun Oct 16, 2005 12:22 pm Posts: 21602 Location: San Francisco
You are correct mowgli2001! Yehuda uses a lead based glass filler which I have been told can be adversely affected by ammonia based cleaners.....of course a torch would be more immediately destructive....a real "oops" moment.
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