It is unknown whether the helmet was a true Precious or not: it may have been but it was always on his head even when originally transformed and likewise disappeared when Ryuuwon changed back into a human. Due to Precious ultimately being defined as artifacts given power by people's dreams, it is possible that the helmet itself became such an artifact due to Ryuuwon's connection to it during his brief departure and that it may have gained some power that others may have used themselves.