Little is yet known of the bonuses gems will provide. It's widely-assumed by most fans that the higher level gems will grant very high bonuses, and that the bonus bonuses won't simply increase at say, +3 per level. That doesn't seem like enough of an improvement to make the months and months of collecting and upgrading required to create a L14 gem worth it.

As for what the gems will provide bonuses to, that's also unknown. Jay Wilson commented on this from Gamescom 2010: ::'''''in.Diablo.d3: '''Can you tell us about gem stats? ::'''Jay Wilson: '''They work much as they did in D2. They have fixed stats depending on which type of item you put them into. We largely copied what D2 did, but not exactly since our itemization is different and stating is different. For example, most of our classes don’t have mana, so that wouldn’t work. But things like casting speed and strength and such are there.  ==Known Gem Bonuses== The only recently confirmed stat is from gem stats were seen on a normal (level 3) [[Emerald]], as seen in the [http://www.youtube.com/watch?v=UNP8QiNbFmU Gamescom 2010 Artisan video]. That gem granted:

The numerical bonuses (but not the type of bonus) from gems changed from D2C to D2X, but clearly there are major differences in more than the numbers. Diablo 3 grants entirely different types of bonuses, and categorizes the socketable items differently as well. These changes are largely due to the game's different combat mechanics and character requirements, but were also somewhat required by the different itemization issues. For instance, [[Sapphire]]s in ; helms/armor grant +mana in Diablo 2, but +mana isn't a viable bonus in Diablo 3, since only no longer share the [[Witch Doctor]] has mana for a resourcesame bonuses.