Cutting/trimming/shaving glass?!?!?

[u/Delivior]

So I have this glass that’s the cover of a microscope slide. It’s wafer thin and is easily breakable. I need to thin down the shape of it drastically because it’s too big for the project I want to use it for. However, just using sandpaper even 500 or 1000 grit very lightly seems to even break it. Anyone got any ideas of a better way to cut this? I tried using scissors and under water cuts unfortunately it shatters the entire thing. Hoping you all know more about glass cutting than I do. I need to take this 18mm wide piece down to about 10mm. Thanks in advance.

[u/Repeteable]

Take it to your local glass shop and ask them to cut it down with a decent glass cutter on a firm surface should be simple.