Yellow Diamond is one of the main Gems in the anime and manga series Houseki no Kuni (Land of the Lustrous). Known for their remarkable strength and high hardness, Yellow Diamond is the oldest gem still active on the battlefield. They are respected for their experience, wisdom, and responsible nature, often acting as a mentor and protector to the younger Gems. Yellow Diamond plays a significant role in maintaining order and supporting the group during battles against the Lunarians.