I am 100% certain the Monster Gems are less than 0.1% Dropchance.
How I am conviced of it?
Well, Hummingbirds.
I am farming Hummingbirds for the gem. So far I have killed more than 4.000 of them the past days - farming at night & hopping channels. (God knows how many Lowbies hated and reported me for oneshotting those mobs with a level 200+ Char)
So untill today: I have every single drop Hummingbirds drop as the following:
294x Hummingbird Wing (7.5%)
040x Ring Bracelet (n/a %)
064x White Flower Hairpins (1.2%)
003x Lv3 EXP Card (n/a %)
001x Blue Orb: Hummingbird
001x Red Orb: Hummingbird
Sidenote: For the Orbs, there seems to be some sort of bug too. The blue Orb is not shown in the Adventure Journal. The Red Orb not even in the Database listed as an Item. (Why are there even 2 kind of orbs for one Monster?)
Anyway - you see. No Gem. Some may call it unlucky but “if” the gems really would have a droprate of 1%, I should have half as many as I got from the Bracelets or Hairpins.
In the end… This makes farming gems for your gear extremly hardcore and for some also frustrating, especially if you can’t farm with your class for the higher rank gems. I am Cryo-Chrono… Chrono Gems farming won’t be easy for me and with a party or DPS friend, there is always the risk the gem goes to the wrong person.
Either those gems become tradable or the drop needs to be increased desperatly to make them a working system.