I'm also only getting one treasure, which I can only assume is not intended behaviour.
Additionally, the gem economy is insane. The default rate of 1 gem per hour is far too slow for the costs. If something costs 24 gems it costs 1 day of real life time, if it costs 200 gems that's over a week. And I know "it's a long term idle game and you can speed up gem generation" but asking players to wait a week for a 1.6x multiplier is too much. I think the cost to generation ratio should be adjusted and/or there should be some sort of gem exchange so those purple gems can actually have some use.