That made her blush faintly. "Not exactly. Just if I screw up, rocks don't burn." She nudged herself straighter and continued. "Also it's part of the theory I was taught. Air and glass for working, gems for focus, rock for grounding, water for cleansing." And wood of course could play any of those roles, which was why Cabalines weren't fond of it. Corbie had been fascinated, though, seeing more opportunity and flexibility than fickleness.