Gem Collection -- any more alternatives?

So I was reading the wikis on this game, trying to find some alternatives to obtaining gems (other than the dungeons and story mode, and other than trying to win the spinning wheel -- speaking of which -- I find it borderline impossible to obtain gems from the wheel).

I saw that there used to be a daily bonus where after 5 days, the player would get 1 gem. Does this still exist? I only have the welcome calendar.

The gems are incredibly expensive for what they're actually worth -- I'm not buying 1700 gems for $120 and using that $120 to buy a monster with a price tag of 1700 gems.

I really enjoy the game, and am trying to find a fun way to obtain gems other than succumb into the regressive micro-transaction format.

Thanks!