Rock Guardian also drops this as well as:
Rock Guardian Shard:
Lore, No Trade Augmentation slot types 7 & 8
All / All; ear, head, face, neck, shoulder, arm, back, wrist, hands, fingers, chest, legs, feet, waist
Tiny - Req level 80, rec level 85
33 AC 25 HME str 0+3 fire & cold +10
Class XII solvent removes this augment
Faintly Pulsating Crystallized Cosgrove Shard
No Trade Augmentation slot types 13 & 14
5 purity - req level 50
You must use Augmentation Solvent to remove and destroy this augment.
Spoiler Test