I am a 6. But it is not set yet. It is at the jewelers, but I am still working our some details.
Nothing is woring with your hands, the setting plays a part too. Try something with a thin band, so that it does completely take over your finger. And I find with dark coloured stones, it is easier to go bigger. With light stones or white stones, I stick around 9mm.
I have an asscher cut ruby, and it is beautiful as well. Wench has a huge 12mm BTD asscher cut kashmir. have you seen that one? AMAZING BTD kashmir!