Questioner
My question is relating to the color of gemstones. In your Ars Arcanum, you always need one color per gemstone for all the different magics. But different gemstones can be different colors, and they give off different wavelengths.
Brandon Sanderson
They do, and in fact rubies and sapphires are basically the same thing. On Roshar, the color is very relevant to certain applications of small permutations of the magic. And so, because of that, they will define, for instance, a blue topaz and a brown topaz as different gemstones, when we would not on Earth. So color is really - it's not going to influence some things, but it does influence others, kind of some minor applications. The answer is, the chemical property is less important than the color as it applies to that magic.
Questioner
My question actually was the wavelength of the color. Because Navani did so much magic, and the wavelength and the sound affects things.
Brandon Sanderson
Yep, wavelength is important. It's going to be a bit of a... I want to say a spectrum, but wavelength…there's gonna be a range that would be workable, if that makes sense.
Questioner
So it would also affect how fabrials are going to-
Brandon Sanderson
It’s going to affect fabrials, it’s going to affect some applications of Soulcasting, and some things like this.