This might be helpful. . .
http://www.vintagerevivals.com/2012/11/how-to-drill-through-glass-video.html

OT, but funny. (I thought you might have meant drilling into glass tile before I opened this thread).

In order to drill into our glass tile backsplash for the screws and anchors to hang our range hood, DH researched online, and then went out and bought special diamond tipped drill bits for the job. He drilled into the tile, slowly, slowly, (slowly), with a wet sponge pressed to the tile near the drill bit to prevent overheating (I think). Took a long time and ended up with one teeny crack near a tile corner (totally hidden by the hood, so np).

Our plumber comes to install the pot filler faucet, along with its screwed-in escutcheon plate backing (the copper water pipe/stub was already in place). Zip, zip, zip with the drill (don't think it was even a diamond tipped bit!) and the job was done lickety-split, and no cracks!

Poor DH!!!! LOL