Does anyone have any idea what we might use these stones for in a Divination lesson?

Chelle paused for a moment to think. She had read about something called 'Lithomancy' in a book, a really long time back. If she remembered correctly, every stone had a different symbol and every symbol could be interpreted to give a different meaning. She wasn't sure if that was what they were going to do that day, but she decided to give it a shot.

"Professor, I had once read about how stones had different symbols which could be interpreted in different ways. This is called 'Lithomancy'," she answered, nervously.

Was that correct? Or did I just embarrass myself?