[semi-extrinsic]

I'm guessing these are done with wet sand paper for the coarser grits (< ~3000), or polished with a soft cloth and paste/polish for the extremely fine grits. At least that's common for related techniques such as lapping, car paint detailing etc. So the fine powder should be carried away in a slurry.

Edit: from TFA:

"Always work wet! Sprinkle some water on the grit before you start grinding! Glass dust is very dangerous and can cause silicosis, a serious lung disease if inhaled!"

[jacquesm]

> for the coarser grits (< ~3000)

I love it how you casually throw that out there. For the un-initiated, outside of grinding lenses: grit 3000 is approximately 6 micron particles and very fine indeed but for this purpose (and gem polishing) it is still considered 'coarse'.

The finest polishing grits go to 100,000, ~0.25 u across.

[dom0]

And for knife sharpening people: 3000 grit (and a leather strip) is enough to almost reach razor sharpness ... with good steel, that is :)

[hinkley]

Even with the wet grinding, eventually the slurry dries out, right? So wouldn't you have to keep your work area wet or mop up regularly during the process?

[wycx]

Unless you are a complete slob, you will clean your work area when you are done for the day, right?

In my experience grinding and polishing samples for petrography, Because the grit etc was once wet, it gets caked-on to everything once it dries. So caked-on that it can be hard to clean everything once it is dry, and if you want to remove it you have to wet it all again. Unless you are stirring up the air with a fan, or trying to remove caked-on grit with compressed air, I do not expect much dust will get airborne. So, clean up whilst it is still wet, and there will be no problems.