It seems that a number of people from the World of Warcraft Forums are having problems with the Relentless Earthstorm Diamond. According to several threads, the said meta gem is not working for melee white damage and spell damage.

If you remember our previous report on the Relentless Earthstorm Diamond (where its stats and ideal classes were discussed), the meta gem grants additional Agility (+12) and Critical Damage (3%) and can be used by both melee and caster classes since it has effects for ranged, melee, and spell attacks - or at least the white damage. It's a very useful meta gem - sans the bug. As of writing, the gem only has an effect on yellow-damage or melee special attacks.

There's good news though, as Blizzard posters Drysc and Hortus responded to the bug reports (separate threads). They both confirmed that the change is not intended and is therefore a bug. According to Hortus, the said bug will be quashed come the next World of Warcraft patch, though Drysc indicated that the bug "looks like it will be hot-fixable" and they are "currently in the process of working on one".

We'll get you updates on which is which when the info becomes available so stay tuned.