https://zh.wikipedia.org/wiki/石女 According to Chinese wikipedia girls who are innately unable to engage in sexual activities with guys usually due to the way the body is structured.
Stone woman : One who was born without vagina (true stone), or with very atypical vagina (false stone) like bone-thick hymen. There're many causes. Poor girl .. But some girl doesn't kneel to her fate! Kudo to your determination, Briana. http://brideep.weebly.com/
BTW, some author extended their imagination of the false stone girl. They created the cause of this false - something like the Pure Yin Earth Core was grown on the hymen. One of the very early work of Gu Long had a girl like this. In today world, there're many baby girls born without vaginal opening. But they are false stone girl. But it's not serious like in the ancient time because the main cause is just the vaginal area skin not opened. We have pediatric surgeon ..