User blog comment:TweedlyDumb/Wublin Reward Results/@comment-28048894-20160402134410

The numbers do seem really spread... Time doesn't appear to be a factor... Though this is a small sample I think the rewards may follow something akin to the scratcher...

With Gems being more uncommon than food/coin ... SEEMS That Gold is most common, then food, then shards then gems.

But this is a really small sample so milage may vary... Haven't bored of tracking it yet so I'll keep plugging in what I get.