Jumping into Gem Grab mode you've got one primary goal: grab gems. I didn't say it was complicated.
The only thing is, if you die you'll drop all the gems you grabbed, leaving them for your opponents to take. That's no good.
Your team needs to grab gems and hold on to them, so there's a natural push and pull. Go aggressive when you need gems, go defensive when you need to hold on to them.
Gems will appear from a mine shaft in the centre of the map - this is obviously going to be a contended spot for both teams.
Lurking nearby in the tall grass is a good idea, lying in wait to ambush any enemies that stray too close.
If you have a long range brawler, you can rain down hell and take care of enemies before swanning in to grab gems, while if you're close range, trying to get multiple enemies in the range of your super is a better idea.
Final push: winning side
Right, so once your team has a certain number of gems, a countdown will begin. If you can hold onto the gems, you will win.
This means that whoever on your team has a high number of gems needs to be protected and needs to evade, as the enemies will be going on the offensive.
If your team loses too many gems, the countdown will stop and the game will continue, so back off a bit and just keep the enemies at bay to secure victory.
Final push: losing side
Okay so if you're the team low on gems when the countdown begins, it's time to get offensive. Find the enemy with the most gems, and take them down.
Your super is especially helpful here, to either blast away of a crowd of enemies and deal heavy damage, or get you in close so you can tap out quickfire.
It's all about getting kills, don't worry too much about surviving yourself. Even dealing damage and dying could help your teammates to deal the final blow and steal the gems.