Read the story at least 30-40 years ago. Book was in English, read in USA, probably a paperback.
The story follows the career of a female cat burglar in Europe (?; I think she was French or Italian). She travels from country to country pulling solo high-value jobs for hire. She ONLY takes payment in the form of blue gems. (Believe it was sapphires, but might have been blue diamonds)
Meanwhile in interludes, or maybe flashbacks, they are relating the events of her life, and how she became a cat burglar.
I don't remember anything about any of the jobs. Other than sometimes the people who hire her, try to get her to take other forms of payment. Despite her insistence of only accepting gems as payment when they hire her to a job.
I do remember the last job, the people who hired her paid her in fake gems. After she leaves with the fake gems, they are laughing it off saying more or less, when she finds out, who is she going to complain to? The police?
Soon after leaving them, she discovers they are fakes, she has a quite explicit graphic flashback, which shows why she only wants blue gems as payment.
When she was a teenager the police grabbed her in a church (I don't recall if SHE had committed a crime, was the girl friend of someone who had committed a crime, or the police just decided to "have fun" with a runaway they caught) They decided to "teach her a lesson" and violated her with their night-sticks. The night-sticks were described as either very heavily scuffed/scrapped/scratched or engraved with patterns so when they hit someone with them, it would cut them up. While she is being painfully violated with the nightstick, and torn up inside, all she can see is a blue stain glass window, which through her tears looks like lots of little blue gems.
I believe the book ends with her in the process of hunting down the men who paid her in fakes.
