It was changed to a random time a while ago. The wait is usually 1-2 hours but I think last month people were complaining they could only go once every 5+ hours.

It's definitely random, and definitely longer than it used to be. Last month I was only able to collect 5-6 gems over the whole two days. Today - I collected one at 7:25-ish this morning, and I still can't get back in, so that's been 2 and a half hours, so far. I'll come back and edit this when I get it and let you know how long it was.

I think the range is up 6 hours - personally I've had to wait at least 4 hours, and other people have said up to 6.

Yeah, the range is definitely higher this month and last then it has been in the past. I was only able to collect 5 gems or so last month, and I checked back pretty darn regularly.

Finally got in - after 3 hours 10 minutes. Got this though :)

What is this?! You find an interesting shrine hidden in the wall of rock... it appears to be for the goddess Apollonia!

as well as...

Thank you for helping... while digging you found...

Green Gem Come back in a while, we need time to clean this area now that you've been here.

I check back every 10-15 minutes.

I had a 3 hour wait this morning as well.

My wait seems to be consistently 3 hours 10-15 minutes. I don't really mind the wait, I just wish I knew if it was truly random, or just different from person to person. I'm trying for the achievement, and after my last grab, I have... Gem Digger Dig 25 gems from the Coda Caves. 24/25

It's been over 4 hours since my last and I can't go back yet.

Oh! Thank you, this explains a lot. Last time I did it two months ago the waits were much shorter; I was wondering what had happened. I don't think I care much for lengthening the waits when there is an achievement for this, especially when those who already got the achievements had the much shorter waits. I was expecting to get a gem every 1-2 hours at the most; these achievements could take several months to complete now. Ah well.

Colored my tigrean galactic. I dont know how long to wait but the gems were fairly cheap so I just bought them to color my pet. I have only got one gem about 20 minutes ago out of the caves.

I've been waiting at least 4 hrs since my last dig -.-

I finally went in after almost 5 hrs.. I wonder how long the next time will take?

I guess it makes sense so as to make them rarer and the pet color rarer as well.

It's not to make them rarer, it's to make the achievement harder to get. Lengthening the wait time between gems to make the colour rarer would be fruitless since you can just buy them from the shop search.

This is to make sure you can't get the achievement in just the first few months haha.. phoey..

oh nos, i forgot all about the coda caves, talk about too late this month lol! ^^

Gem Digger Dig 25 gems from the Coda Caves. 11/25