I have scanned slabs on my Visioneer One Touch 9320 with nice
results. Not as nice as a professional photo but plenty good enough
to see the details. I scan on default photograph setting at 150 dpi
normal contrast and brightness. I have tried 200 dpi and fiddled with
the contrast and brightness but always go back to the default
settings. Suggest you coat the surface with either a clear matte
spray or use a good wax (I use Briwax) to sharpen the colors. Does a
Oh...be careful not to scratch the glasss plate.
Cheers from Don at The Charles Belle Studio in SOFL where simple
elegance IS fine jewelry!