Gem Perfection
- Gem Perfection
- Passive
- Gives the Jewelcrafter the chance to cut uncommon quality Northrend gems into perfect gems.
Gem Perfection is a passive trait exclusive to Jewelcrafters. It gives a chance when cutting uncommon Northrend and Cataclysm gems to cut it into a "perfect" gem, slightly raising its stats (by 15% or more).
Quest source
Once you reached Level 50, you were eligible for the starting quest offered by any of the Northrend starting area trainers (These quests seem not to require a certain Jewelcrafting skill):
[80] Gem Perfection- [80] Gem Perfection
[80] Gem Perfection- [80] Gem Perfection
Notes
The exact proc rate for this skill is still unknown because of insufficient data. However, initial findings estimate the proc rate to be 10-20%.
For example, one crafter found a 20.45% perfect cut rate out of a random sample of 200 gems.[1] This crafter later made a table showing results for over 650 gems and found an overall rate of 20.22%, but varying rates depending on the type (Bloodstone, Delicate, 49 cut – 18.33%; Chalcedony, Solid, 57 cut – 28.75%; Dark Jade, Jagged, 139 cut – 20.11%; Huge Citrine, Luminous, 64 cut – 20.00%; Shadow Crystal, Purified, 136 cut – 17.07%; Sun Crystal, Smooth, 64 cut – 20.00%).[2]
Patch changes
Patch 4.0.3a (2010-11-23): Has been removed as a trainable skill and is instead a passive profession ability. When players reach the appropriate skill level, they will start getting bonuses from cutting perfect gems. 
Patch 3.0.2 (2008-10-14): Added.
References
- ^ Zebeyo 2008-12-21. Gem Perfection. Wowhead. Retrieved on 2011-03-22.
- ^ http://www.zebeyo.dk/kalazia/gems/ [dead link]