From LSWiki

Stone Resistance is DEAD! R.I.P. It isn't here anymore. Don't bother looking for it in-game.

Class: Resistance Skills
Attribute: Vitality
Pedagogy: Body Alteration
Practitioner Term: Stone Resistor
Hidden Skill

This skill represents the conditioning of one's body to resist being damaged by the amalgam stone and essences that partake of its
nature.

Stone resistance can be increased by exposure to stone damage, changing more quickly according to one's somatic adaptability.  It
will decay over time, weakening more quickly according to one's somatic adaptability.

 See Also: stone affinity

Trainers