I do not know if this is a bug or normla , but has a few days of gems together and the next day or two , disappears. Already he had Level 4 and now I start again.
I do not know if I 'm the only one that this happens, but I want it fixed that, I do not want to collect gems …
PLS !!!
Fun fact : If you die gems get dropped, you have only 30seconds to get them back or its gone forever.
It’s a way of balancing the game, rather than an EXP penalty better your gems.
so remember to save up precious gems on storage before going to new-potentially hard maps 
WooW !!! I did not know that, thanks for your answer , now that already do so !!!
really thanks!!!
To add on. Removing a gem from a gear reduces 1 star from it. Just saying.