How often is Crystal Caverns populated/camped?
 

In particular, the geonid tunnels.

afaik it's fairly quiet most of the time....quieter than it should be as people never deviate from their well trodden XP paths.

I would expect at least the geonids to be camped 24/7 because of how much money they average, since they can drop - and frequently do drop - chipped diamonds and chipped blue diamonds with vendor for 200p.

If not that, then the velium weapons and bars from the orcs is worth a lot too.

CC is generally empty. Not sure what kind of gems the geonids in CC drop, but guessing they're not as valuable as what the ones in WL drop.

Its generally pretty empty, but that already means its full. Usually youll see someone solo or duo camp the entire tunnel of spider or geo so 2-4 people in zone = camped

Gem drop rate in CC was pretty bad when I leveled there on my ranger. And I never saw anything like a chipped diamond / blue diamond.

gems drop off named geonids only, I've had 4 named spawn in one rotation before. I've also gone 3 rotations without a named /shrug.

Looted a chipped diamond and chipped black sapphire last night

You're better off doing the geonids in WL later on.

What level are the CC geonids?

like 35-38