Small Prismatic Shard

As of 2.4.1, I can confirm that the bug is still in effect.

However, only Blood Elves can benefit from this bug. Due to their Racial Ability it allows them to gain ten free skill ups by converting a Large Prismatic Shard into three Small Prismatic Shards and back again.

Even though the ability appears gray, a Blood Elf enchanter can make it from 335 to 345 skill enchanting at no cost to them.

Only the conversion from three Small Prismatic Shards to one Large Prismatic Shard is effected by the bug. Therefore, you will only have the chance to gain skill ups half of the time (since the other half of the time you'll be converting back to three Small Prismatic Shards). This can make for a fairly lengthy session in gaining your ten free levels. While I was able to get the first few levels quickly, it probably took about 20 minutes to get all ten.

Let's clear the popular belief that there is a bug with this skill.

It's not a bug, a bug would imply that there is a problem somewhere with casting this skill or with the player and his/her's ability (and ultimately get fixed).
The reality is that Blood Elves get 10 extra points (attainable levels), so to say (duh). Meaning that, where a skill would turn gray at 10, would only turn gray to Blood Elves at 20. This spell turns grey to others at 335, to Blood Elves it's 345 - allowing us 10 more levels from using this. Cha'ching.

Here is an example from wowwiki - professions page...

The Draenei Jewelcrafting skill bonus of 5, for example, means that a recipe that turned from orange to yellow at 30 for other races would not turn yellow until 35 for a Draenei jewelcrafter.

This is not a bug, it's just the bonus we blood elves get from our enchanting racial. So, be sure to see this in game for as long as the Sin'dorei have this benefit.

Source: Wowwiki - Profession

Please + this so that others may understand. Thank you. <3

This pattern can be purchased by:

Felannia <Grand Master Enchanter> in Thrallmar, second floor in the tower with the Alchemy/Herbalism trainer. (52.36)

Johan Barnes <Grand Master Enchanter> in Honor Hold, second floor of the Wizards Tower (53,66)

Individuals with Scryer faction can also purchase this in Shattrath City from High Enchanter Bardolan <Grand Master Enchanter> in the main building on the Scryer's Tier (43,92)