I’m experimenting with a gem report for each class. It is easy enough to generate a list of the most popular gem choices. Like a lot of the other player-configurable options in WoW, you get the infamous power law distribution: a few choices that many players make and a long tail of left-of-centre choices each of which is made by only a few players.

For priests (level 70, pre-patch-3.0.2) we get something like this:

Gem Colour Popularity
Discipline Builds
Steady Talasite green 75%
Teardrop Living Ruby red 64%
Royal Nightseye purple 54%
Luminous Noble Topaz orange 45%
Mystic Dawnstone yellow 39%
Teardrop Blood Garnet red 32%
Powerful Earthstorm Diamond meta 28%
Solid Star of Elune blue 24%
Teardrop Crimson Spinel red 22%
Insightful Earthstorm Diamond meta 21%
Holy Builds
Royal Nightseye purple 80%
Luminous Noble Topaz orange 76%
Teardrop Living Ruby red 75%
Purified Shadow Pearl purple 55%
Purified Shadowsong Amethyst purple 42%
Teardrop Crimson Spinel red 35%
Teardrop Blood Garnet red 34%
Teardrop Crimson Spinel_35489 red 27%
Luminous Pyrestone orange 24%
Royal Tanzanite purple 23%
Bracing Earthstorm Diamond meta 23%
Luminous Flame Spessarite orange 22%
Shadow Builds
Runed Living Ruby red 115%
Glowing Nightseye purple 71%
Runed Crimson Spinel_32196 red 67%
Veiled Noble Topaz orange 37%
Glowing Shadow Draenite purple 30%
Runed Blood Garnet red 29%
Potent Noble Topaz orange 27%

As usual, the gem names link to Wowhead.

Percentages can be greater than 100 because the same gem can be used in more than one socket per item or per character. That doesn’t matter really. The percentage value just forms a sort of popularity index which can be used to order and rate the options.

It would probably make sense to group the gems by socket colour and/or by the type of stat granted since these are the starting points for deciding what gem to acquire. I’ll add that to the next version of the report.

It is possible to generate other tables that would show:

  • popular gem/gear combinations
  • popular sets of gems per character

I’m playing with queries for both of these but the data doesn’t seem to show a lot of clear patterns. Any suggestions for other ways of analysing gem useage would be welcome.