Re-polishing a Lapis Cabochon
This is a flat topped Lapis cabochon which the jeweler had accidentally put into the Rhodium plating solution. The harsh acids ate into the sureface and destroyed the polish. He asked me if I could re-polish it to make it look like new again. I said, "Sure!"
Jewelers have asked me why plating solution or pickling solution hurts the polish on stones like Lapis or Coral but don't hurt other stones. The reason is, most Lapis stones contain at least tiny amounts of Calcite in and among the crystals of Lazurite which make up Lapis Lazuli. The harsh acidic solutions eat up the calcium carbonate of the Calcite very easily and rapidly. That leaves the etched surface. Coral also contains calcium carbonate and is just as vulnerable.
Below, you will see photos of before and after re-polishing the Lapis.
