I didn't even know these things dropped ore until I suddenly saw one in the loot list.
Turns out these things are really good for farming those Small Brick of Ore you need when you are trying to skill up on your Smithing.
Camp out near Najena entrance. They are easy to pull, not social, and have a decent drop rate. I got 40 bricks from my last run, which directly saved me from buying two stacks of bricks which cost me 13,5pp each in Neriak (15pp each in Oggok).... so overall, roughly 30pp saved on smithing mats while at the same time getting other loot and experience from the Dervishes!
Even when these turn grey I'll still be farming them for bricks so I can reduce the cost of crafting banded, thus increasing the profit margin!