Captain Kid vol. 5-6 - dart+stone

If you like girls turning to stone, this scene is for you. A rare petrification scene.
Captain Kid's mermaid/human girlfriend is hit with a poison dart while being chased by bad guys. Captain Kid carries her to safety, but the dart's potion has already put the girl to sleep.

She slowly turns to stone as well.

By volume 6 she is revived. They spend a whole story arc on figuring out how to save her.