serpentinised

/S ER1 P EH1 N T AH0 N AY1 Z D/
verb
  1. 1

    To convert (another magnesium silicate mineral) into serpentine

Source: https://en.wiktionary.org/wiki/serpentinise, https://en.wiktionary.org/wiki/serpentinised, https://en.wiktionary.org/wiki/serpentinize