"Speed Leveling Legendary Gems
Gem Upgrade Chance / Greater Rift Level Compared to Gem
----------------------------------------------------------
0% / -7
1% / -6
2% / -5
4% / -4
8% / -3
15% / -2
30% / -1
60% / +0
60% / +1
60% / +2
60% / +3
60% / +4
60% / +5
60% / +6
70% / +7
80% / +8
90% / +9
100% / +10
The most efficient way to get a level 25 Legendary Gem would be farming "9" Greater Rift Trial Keys, which drop off normal rift guardians/bosses. Than proceeded to complete Greater Rifts Level: 13, 16, 19, 22, 25, 28, 31, 34, 37; Which allows a 100% chance to upgrade your gem to tier 25 | PS. don't forget to hit upgrade gem every time you complete a greater rift"
Is that true and tested? Cant believe it just takes 9 greater rifts to get a rank25 gem, since that would be really easy and yea.