Malachite
From Shadow of the Throne Wiki
Appearance: An opaque, banded stone; the colors in the bands range from a very light green to almost deep green.
Description: It is said to aid in the regeneration of body cells, creates calm and peace, clears subconscious blocks, and aids one's sleep. Malachite is worn by some superstitious Threshold nobles to protect from demons and sorcery, though Dynastic occultists often consider this laughable.