Her talons are tipped with quartz as well, one claw on each rotor hub on her wings. They aren’t the best pressure sensors designed, but thanks to magic, you could do more with the piezoelectric effect than back home. You haven’t yet figured out how to electrically monitor magic in a crystal, but Twilight had figured out how to magically monitor electrical charge in one. She said the talon-tips were necessary because she was tired of having to guess how much force she applied with her own claws.