lvl 20 skill gems.

ive read from
https://mobalytics.gg/poe-2/guides/high-level-gems

In Early Access, this information can be datamined.

81 or lower: 0 (level 20 uncut gems are absolutely banned from dropping)

82: 1 in 81 uncut gems will be level 20

83: 1 in 33

84: 1 in 19

85: 2 in 35 (getting even one level 85 item requires 'stars aligned' luck, so this is in no way practical)

No known ways to get level 86 or higher loot exist at the moment, but the game files contain probabilities of 1 in 5 for level 86, 1 in 2 for 87, 8 in 9 for 88 and 32 in 33 for 89.

As uncut gems are quite common, running tier 15 and tier 16 maps that are irradiated and on corrupted ground will eventually find you the powerful lategame upgrade that is level 20 gems.

Warning: Level 20 gems require you to be character level 90 to use them.

how ever my brother was mapping lvl 81s an had a 20 skill gem drop. So im curious if anyone else has had this happen. I dont want to waste 16s on 81 mobs if the skill gem doesnt drop. maybe my brother was mistaken. I have to clue an just dont want to waste the way stones.

Level 97 and have been running 150 rarity since maps and I've found one.

I believe rare monsters count as +1 and bosses as +2 levels which could be why he dropped one in lvl 81 map. (A rare or a boss mob dropped it)

Don't remember if strongboxes also can roll +1,2 etc here as well like in poe1

They are too rare atm!!

As I'm writing this: I just got my very first Uncut Skill Gem Level 20 in a Level 80 Map by a Mob.

My Rarity is as 94 % and I'll post you the modifiers of the Map in an Image.

So it doesn't seem it would only drop on high End Maps.
I could think of a higher drop chance but definitely they are not excluded from level 80.

They buffed the drop rate recently. I don't think rarity increases the chance of a gem to drop tho.

Just make a few 4 links and corrupt them.
Waiting on them to drop is a waste of time, like so many things in this game ;-)