[smccleme]

If it holds water, I wouldn't rotate the glass. Your new silicone job won't be nearly as strong as the factory's. I'd cover the edge to hide the damage, and somewhat increase stability by using aluminum angle iron, as illustrated here:

http://www.bcaquaria.com/forum/equipment-talk-section-14/black-silicone-look-68354/

I've done this cosmetic repair on two chipped tanks with good results (ie, haven't had a problem for years).