[@Loony]Well, in the show, we've seen the darker sides of all the gems by now, including rose.
Amethyst just doesn't care. She's a walking mistake and just wants to be left alone at times.
Garnet is an extremist, and loses sight of things like safety and reason when in the heat of battle. 
Pearl lives solely on perfection. She needs everything to be a certain way, and will work endlessly until every dust particle is how its supposed to be. She can't handle certain truths, like how Rose didn't tell her everything. She saw that as an impossibility, and refused to accept it.
Rose was shallow. She saw the humans as simply things, and when faced with Greg's decleration of love at the temple, she told him that she had no time to play with him, and had laughed right in his face when asked about love and their situation.