The unlikely combo of perfect Crimson/Joyfulness would yield +12 minimum damage. If the jewel was rare, it might also include +24 max damage (with another perfect pairing: Carmine/Carnage, astronomically rare).
More reasonable would be a Crimson (5-8 min) Jewel of Carnage (11-15 max), and that's plenty rare enough by itself!
The Silver prefix caps at +60 AR.
Up to 9 Dex (of Daring) and 6 Str (of Virility) could be equippable @ lvl 29.