Note to new readers. Blizzard is changing these gems in a future patch. You may want to hold off before spending a ton of money on regemming.
Suicidal Zebra and Graylo have commented about the meta-gem requirements for the Chaotic meta-gems.
Chaotic Shadowspirit Diamond Activation Requirements:
New: Requires more Blue Gems then Red Gems.
In my opinion, they are both using a sub-optimal gemming pattern to take advantage of these gems, and as a result, their valuation of these meta-gems is lower than it should it be.
This is what I think the optimal gemming method is:
1. I assume that our goal in gemming to maximize our Red primary stat (Str, Int, Agi) while still activating the meta-gem. We can always fiddle around with the secondary stats with reforging.
2. I assume that we will hit the socket bonuses. Since we're already messing around with red and blue gems, it's a small step to get the yellow sockets too.
Description of problem
Let each gem have a "meta-score". This how that gem affects the count for activation of the meta-gem. For example, red gems are -1, and blue gems are +1. The end goal is to have a net meta-score of +1, as that is exactly the minimum to activate the meta-gem.
|Socket Colour||Gem Colour||Meta-score||Red Primary Stat Amount|
As you can see from the table the best gems to maximize both Meta-score and the Red Primary Stat are Red, Green, and Purple. You want to put Red gems in Red sockets and Purple gems in Blue sockets. That leaves Green gems in Yellow sockets as your method of balancing the Red gems.
The second tier of Orange and Blue are last resort gems, only to be used when the number of sockets doesn't work out nicely.
(Note: for the purposes of this algorithm, prismatic sockets count as Red sockets. You will also need to keep track of your current meta-score as you are gemming.)
1. If half or more of your sockets are Red, put Purple gems in Red sockets until the number of empty Red sockets is just less than half of the number of total empty sockets.
2. Put Red gems in the empty Red sockets.
3. Put Green gems in the empty Yellow sockets until your meta-score reaches +1 or you run out of Yellow sockets.
4. If there are empty Yellow sockets remaining, alternate Orange and Green gems until you run out of Yellow sockets. (If you don't care about socket bonuses, you can use Red gems instead of Orange gems in this step.)
5. If your meta-score is 0 or lower, put Green gems in Blue sockets until your meta-score reaches +1. (You can use Blue gems in this step if you still want more of your Blue stat.)
6. Fill the remaining empty Blue sockets with Purple gems.
That looks a little bit complicated, but the underlying idea is fairly simple:
You use your Yellow sockets to balance your Red sockets (Green gems against Red gems), and then you zero out your Blue sockets using Purple gems.
The extra steps are just to compensate for cases where the number of sockets doesn't easily match the basic idea.
My character right now (in DPS gear) has 9 Red sockets, 1 Prismatic socket, 9 Yellow sockets, and 2 Blue sockets. Remember that Prismatic counts as Red.
1. My Red sockets are less than half of my total sockets (10 out of 21) so I move to step 2.
2. I fill all 9 Red sockets and 1 Prismatic sockets with Red gems. Meta-score is -10, with +200 primary stat.
3. I put Green gems in all 9 Yellow sockets. Meta-score is -1, with +200 primary stat.
4. I don't have any Yellow sockets remaining so I move on.
5. Meta-score is 0 or less, so I add 2 Green gems to 2 Blue sockets to bring it up to +1. If I needed more hit, I could use 2 Blue gems instead. Meta-score is +1, with +200 primary stat.
6. I don't have any remaining Blue sockets, so I am finished.
Net result: Meta-gem activated, +200 primary stat, all socket bonuses. If I have excess hit rating from the Green gems, I can use reforging to convert the extra hit rating into another secondary stat.