I got riled up because I could perceive no "opinion" in the context of our first post. In fact, I could perceive no point of view at all except to point out the fact that Quartz is an organic material. Anyway, I do apologize for my tone. I may have been too paranoid. My father put together a nice monaural system for my mom, in the early 1950s, even though he had no particular interest in either music or audio electronics; she was an opera and classical music lover, however. I grew up surrounded by her music and her singing; she was also an accomplished opera singer. He built a cabinet for what must have been an Altec Lansing 604, and he bought a Harman Kardon Festival mono receiver. There was a Garrard record changer as a signal source. By the 1960s, I was a jazz buff listening in college to whatever I could afford.
"Antique" systems are welcome here, as far as I am concerned, and I think I can speak for most others. I've got a system based on Beveridge direct-drive electrostatics; Beveridge the company went out of business in 1982 or thereabouts. It is fronted by a Quicksilver preamplifier that dates to the mid-1980s, and the phono source is either a Lenco idler-drive or a Victor TT101, both of which are early 1980s or earlier in the case of the Lenco. The biggest, maybe the only, improvements in audio equipment since the 1980s, IMO, has to do with solid state gear, and only because of better transistors and ICs now available compared to "then". CDPs are a whole lot better now than were the earliest products, IMO. Certainly, speaker design may be said to have gone down hill in many respects, even though the technology for making drivers has made advances in terms of computer-aided design (CAD) and 3D shaping. Yet, I don't hear any miraculous new speakers these days, when I go to shows.