In Temple Run 2, gems appear randomly. How often do they appear? Is there any way to make them more common?
I assume that Gems are a random spawn of Power Ups. You can see I'm interested in the spawn rate of Power Ups myself.
Given that Gems are treated the same as other pick ups, you can increase the chance of spawning them with the "Pickup Spawn" boost in the "Abilities" menu for each character (when the boost is purchased it is permanent and applies to all characters).
Spawn X% more frequently
Where X increases in steps the more coins you spend.
To be honest, I found a way which at least helps me... What I do is take alternate turns, like if I have taken a turn to the right, I will have to take a turn to the left next, though this happens only when you have a option to do so, otherwise follow the trick, but when the dual path comes, remember your last turn and take the opposite turn then... This increases the probability of gems appearing A LOT.
To get more gems you must die before hand with half way energy. This works for me.