Gem of Inner Might

From the Clutch of Kings (Rehir) quest, introduced during the On Bended Knee event.

Gem of Inner Might
Value: 0 10 Burden Units
This gem can be place into a piece of Noble Armor. If so, it will imbue the armor with a very potent Strength Spell that will affect the wearer. Combine with a piece of Noble armor to infuse the armor with the Inner Might spell. This item cannot be sold.