Recognising filled diamonds

Jewelry Discussion
1

Hello everyone, Would just like to say thanks to all those that
offered advice. Have found the idea of using drain cleaner to remove
dirt works very well. Regarding the problem of filled diamonds, is
there anyway of recognising these before you start work on them,
Many thanks Roger

2

There is a distinctive color flash most filled diamonds give off
under the proper lighting and magnification.

Daniel R. Spirer, GG

3 
   There is a distinctive color flash most filled diamonds give
off under the proper lighting and magnification.

There is a combination flashlight and loupe available which
provides “dark-field illumination.” This allows one to see the color
flash with greater ease. David Barzilay, Lord of the Rings