I think its a spoof. For starters - quartz is indeed hard (and hard means brittle). You can't extrude it or bend it. The only way you could make these things would be to sputter coat some metal substrate. The pictures obviously don't look it. They're certainly not carved - it would take a jeweler months to do a single guitar. Breakage would be horrendous. The music biz is kinda small in the corporate manufacturing world. Especially compared to toasters, tv's, etc.. If something like this were real, it would require a company the size of Fender or Ibanez to get the stuff made. This is not something 6 guys in a shop in TN are doing.
The only remaining possible way to make the frets that I can see is to basically superglue quartz dust.