I've only just noticed I've not had a Gem from mining since the update. *sadface* I may have missed the annoucenment, can someone point me to it if there was one?
There are multiple upgrade cards for getting more gems, when you get those it seems to me like I get gems even more frequently than I did before the switch.
IIRC there are three gem upgrade cards. Like Fleep, I think I'm at or better than I was before. The only thing I've noticed is that I've gotten no walloping big diamonds, but again that just may be the luck of the RNG.
I have 4 upgrade cards and I'm definitely getting less gems, even though I use Rookswort whenever I mine to keep my mood above 95%. It may be part of the 'leveling of the playing field' that TS has told us of.
The last card I bought said it would give me a 8% chance of finding gems. I'm finding I'm getting slightly less than I used to, but still get some gems every time I go mining. No diamonds yet, but I've gotten all the others. Sometimes I've even gotten 2-3 gems from mining the same rock. And usually that happens when I pick a small rock, so maybe good things come in small packages?
No gems for me until I got an upgrade card. I really missed gems! Despite the bag space the hog, getting a gem brightens up the drudgery of mining. I don't feel the same way about music blocks dropping from trees. In fact, I have tended to pass up most of the cards that offer a chance of getting a special gift from harvesting.
I received a diamond from mining, a day or two ago. They're out there. I usually just hurl all my gems into shrines to get the extra IMG (which always looks so weird without html brackets around it), which has the nice side-effect of keeping tabs on what gems you've earned recently. There was a diamond in there, I'm sure of it. I don't know if the cards stack or if the %'s are an accumulation, but I have at least an 8% chance of gems when I mine.
(edit to change from 6 to 8%, double-checked my cards)