The Basic Instinct actress, 66, who was abused by the molester, also saw her maternal grandad Clarence Lawson sexually abusing her five-year-old sister when she was aged eight, and has now recalled how he would also beat her grandmother.
She told The Times: "He was a pedophile and a sexual deviant. There wasn't anybody he wasn't trying to have sex with. He'd have sex with a chair leg.
"My grandfather was just out of control. He was very abusive.
"He beat the living s*** out of my grandmother – I think that she was numb to having any feeling."
Stone previously revealed in her memoir The Beauty of Living Twice she and her sister Kelly were sexually abused as children by their granddad when they were toddlers, and that their grandmother locked the door on them before he molested them.
Stone went through years of therapy to get over the abuse, adding: "I really came to understand that it had nothing to do with me. I could have been an inanimate object.
"Frankly, it has zero meaning to me anymore. I feel bad that this person lived with that illness, like I feel bad when someone has leukaemia or cancer.
"He had a terrible illness and his illness really affected other people and he should have been in quarantine his whole life."
Stone, who is single, finds it harder to forgive men who are deliberately cruel. She added: "I've been in relationships with men who have intentionally lied and done other things to me that have been really hurtful. Sometimes I think that might have hurt me more because they're not actually sick.
"They're just overprivileged because of who they are and they think they can be cruel and mean to people."