What gemstone might be used amplification (augmentation) Fabrial?

[Steven]

Short Question, long exposition.

Question: If a Fabrial were to be made in order to amplify the sound of something (say, an instrument), what gemstone do you think is most likely to be used/would work best there?

Expo:

I'm a novice luthier who is working on one of my first few guitars. I'm building this for myself, and I'm trying to include references to all of my fandoms, spirituality, ethics, philosophies, etc. One thing that I wanted to include (especially with Rhythm of War's new release) is a reference to the Stormlight Archive, and I thought adding some gemstone element would look really cool. I was thinking up a way I could tie it into the canon of the Stormlight Archive, and (since this guitar is electric) I thought it would be a neat reference to add the gemstone as if the guitar were amplified by an augmenter gemstone rather than an electrical amp. I looked in the Ars Arcanum of the books and I saw the quote "I am guessing that any one of the ten Polestones would work." Now technically I know this would give me free reign to put whatever of the Polestones that I like in there, but I'm curious as to your thoughts of what might be the most applicable stone, based on their properties and uses that have already been revealed. Outside of that, what do you think would look coolest or be a sneaky cool reference? The guitar is made of Aromatic Cedar and Walnut, which give it red-and-gold tones. I'm planning on adding a piece that could change colors at my discretion, so my guess is that anything within the purple-red-yellow gradient (as well as clear, white, or black) would fit in well, whereas something a different color might look out of place

Thanks!

[Weltall]

My guess is that an augmenter fabrial for something like this would make use of a musicspren but unless RoW has something to say on the subject (I've just barely started it) we don't know what stone(s) they might be attracted to, so there isn't likely to be any canon guidance there.

However, since there's an association between the polestones and the ten Orders and we know that the Lightweavers specialize in manipulating both light and sound waves, you probably couldn't go wrong with a red stone representing their associated polestone, garnet.

Edited November 24, 2020 by Weltall

[Karger he/him]

Decent reasoning.  You could also copy the emotion fabrail as it would certainly be useful for a rosharan music performer.

[Honorspring]

The gemstone wouldn't be particularly important, like you said, though ruby seems the best pairing with cedar. However, the metal for the fabrial cage should be steel because it is the pushing metal and it would be pushing the sound out rather than pulling it in. I would also include some zinc and brass wires connecting to the volume control since they "soothe andriot" the spren inside the fabrial

[Halyo_Alex he/him]

I kinda wanna say Amethyst if only because it's used for the essence of metal