Eye of RokGus

[jadier]

Hello all,

Trying to get my Sorcerer's Skullcap. On the last of the four gems, the Eye of Rokgus. I've ground out 3 levels in Nurga in the Slave Pits killing burynai slaves and their placeholders. I've gotten several legion gis and belts, but no Eye of Rokgus. My guess is that it's just quite rare, but the wiki says "used to drop off Chief Rokgus" so I just want to confirm:

On Green, does this gem drop off the slaves or the actual chief himself?

Thanks!