How to get upgrade stones?

[Breehit]

I wonder what I am doing wrong? I do a ton of pet battles every day, all different levels (I am up to 340 pets), but I have not been able to get a single upgrade stone. Is there a trick to it? Do they just randomly drop at the end of a winning battle? Or do I need to do something special to make one appear?

[Foust]

I began to think that either I was cursed, or the stones were bugged. I have been on a collection spree the past couple of days and probably captured at least 30 new pets. I finally got one while capturing a beetle in Uldum. They don't seem to "drop" very often. The one I got was the blue kind. I did read that higher level pet battles have a higher chance to drop them. When you do get one, it displays with the rest of the end-battle information, after you see the XP and whatever pet you may have captured.

[Quintessence]

I've had more luck with stones coming from the daily bags than from successful wild pet battles, but it took me a few days to actually find one from anywhere. I stopped "looking" after a while and forced myself to not bother/care. I found that this mentality made my experience less stressful. The stones are just a nice perk and very rare, so I've learned to not hope for one while pet battling.

Even so, don't stop trying. You'll find some eventually!

[Mairin]

I've concluded that either the stones are a lie...or I'm cursed...or both. With some of the recent pets I have WAY too many poor pets in my list atm