[ejolto]

I'd be scared of scratching the glass of the scanner.

[laputan_machine]

I'd imagine you should be able to place a thin sheet of perspex - or something similar - to protect the glass

[ZiiS]

PCBs rarely contain diamonds. For decent scanners with real glass this is not a major problem.

[iudqnolq]

Pockers rarely contain diamonds. Phone screens are real glass. Yet phone screens get scratched over time.

[Scalene2]

A lot of it is probably quartz in dirt.

[stavros]

Cling film on the bottom?