So many analog clocks and watches say “QUARTZ” prominently on the face. Why is that such a big deal? I mean, I guess it explains what kind of oscillator the watch/clock uses, but isn’t it pretty commonplace today?
Marketing.
Manufactures of cheap products can’t help but put generally useless attributes on their products. Watches are no exception. Cheap audio products are another example.
For a brief moment quartz watches were perceived to be the superior luxury technology. (There was for instance a quartz Rolex, and it was one of the first.) Nowadays, emblazoning “quartz” on a watch is about as tacky as putting “injected” on the back of a car. Almost all watches sold are quartz based. It just tells you that the cheap watch you bought will keep relatively good time, doesn’t need winding (and will eventually need a new battery.)
Even entry level mechanical watches are much more expensive than quartz, and this serves as a form of inverse snobbery. High end manufacturers that make quartz watches never write “Quartz” on their products. Manufactures that make nothing but cheap quartz watches will usually write in on.
[off-topic]
Confusion may arise because there are at least four distinct reasons that a watch may incorporate a crystal or gemstone:
[ul][li] Quartz crystal to give an electronic oscillator a fixed frequency.[/li][li] Sapphire (transparent) crystal instead of glass to make the watch-face scratch-proof.[/li][li] Rubies to provide stable low-friction bearings, better than metal-on-metal.[/li][li] Diamonds as cosmetic adornments.[/li][/ul]
Assuming a watch isn’t mechanical, is there any option for the timekeeping mechanism other than a quartz oscillator?
RC Time Constant
GPS
WWV/WWVH
LORAN
Cesium
Rubidium
There is also Seiko Spring Drive. It has a quartz oscillator but it only regulates the escapement of an otherwise entirely mechanical watch. It is a remarkable technological achievement and the price reflects that. They start around 3500.
Curiously, a quartz oscillator is at the core of many systems, even when not directly identified. Cheap rubidium atomic clocks are just quartz oscillators that are conditioned by the adsorption spectra of rubidium. Even the GPS satellites, that use either hydrogen masers (Galileo ) or cesium clocks (GPS) as the long term master oscillator use rubidium clocks, and hence may have a quartz oscillator in there.
The reason is that over short time periods a quartz oscillator is very stable (aka, noise free, aka low jitter, aka low phase noise). Although atomic clocks have the highest accuracy, they are noisy, and not as useful for short term timekeeping.
At their core both the balance wheel escapement and a quartz crystal oscillator have a lot in common. They are both mechanical oscillators. It is a matter or detail how they are energised and their natural frequency tapped for timekeeping duties.
A special mention must go to the Grand Seiko spring drive mechanical watch. Both mechanical and electronic it requires no batteries, is self winding, and has the accuracy of the best quartz timepieces. It however comes at the price of a reasonably high end mechanical watch. Its obvious feature is that it doesn’t tick at all. The second hand moves with a continuous glide. Very cool.
ETA - ninja’ed on the spring drive. Nice that someone else knows about them.
It’s a historical thing. Originally, watches were (and some still are) extremely finely machined and constructed clockwork devices. The accuracy of the watch was very dependent on the literal mechanical design and construction of the watch itself, so that an ‘accurate’ watch might be one that varies by five seconds a day versus what it was set to originally. So over the course of time, the time your watch displays gradually drifts from where you set it originally. And you had to wind a mechanical watch daily or nearly so.
Sometime in the 1960s, the quartz oscillator came into common use, and revolutionized the watch industry- your average quartz watch accuracy changes by hundredths or thousandths of a second each day. Dramatically more accurate than the old mechanical watches, and since it all runs off a battery, no winding or anything like that.
The catch is that while the original quartz watch was a very high end one (the 1969 Seiko Astron, at the price of 450,000 yen, equivalent to $1250 in today’s dollars), over the next decade they became inexpensive enough to where the cheapest watches are quartz watches and keep terrific time relative to the old mechanical style watches. But they all still say “Quartz” on them because it was a marketing tool originally- high end quartz watches in the late 1960s through the 1970s all said that as a statement that they were quartz watches and therefore very accurate.
So it’s meaningless today, and it’s a historical holdover from when quartz watches were high end.
Point taken, but I’ll dismiss GPS, WWV(H), and LORAN, since they basically boil down to asking someone else what time it is.
I suspect that an analog RC circuit will to have unacceptable accuracy for long-term timekeeping.
Cs and Rb are atomic clocks. They have their uses, but are there any self-contained (i.e. not relying on a radio signal from the NIST atomic clock) , consumer-grade atomic clocks out there?
Let me rephrase my question:
Is there a practical, affordable option for consumer-grade timepieces that provides accuracy comparable to that of a quartz oscillator?
You can get a basic rubidium atomic clock for well under $1000. Typically they are just a box with a one pulse per second output. It is left to the user to put a display on it. As I note above, they are still actually quartz oscillators conditioned by the rubidium source.
As beowulf notes, you can get a good oscillator with MEMS. I would note that it is still a mechanical oscillator based upon a crystal (which gets you the very high Q you want). Just crystalline Silicon rather than crystalline Silicon Dioxide.
Transistor radios used to advertise that they contained “integrated circuits”, but today that is not even mentioned, let alone prominently labelled (today they might be labelled as using a “phase-locked loop” or something else, it has to be something). Maybe the deal with quartz is that there are still a few viable alternatives? Or that, like the radios, they feel obligated to print something?
I have done a bit of* Googlage*, and reached the tentative conclusion that a cheap quartz watch is going to be something like five times as accurate as a fancy mechanical watch costing thousands or tens of thousands.
I appreciate this is can only be a very broad generalisation, but I would be interested to know if that’s felt to be in the right ballpark.
Yup, cheap watches are significantly more accurate than the expensive ones. If you buy an expensive watch, it’s not because you want to keep time really well.
Consumer timekeeping devices that use things like the radio time signal or GPS usually also have a quartz oscillator in them, to maintain reasonable accuracy either between updates from their external time source, or when they are offline/out of range.
Which is why I bought a quartz Tag Heuer; spending that much money on a watch, the thing better keep damn good time 
My guess is that now integrated circuits are SO commonplace that it is more likely that we’d see “vacuum tubes” prominently labeled (or shown) on electronics. AFAIK, that’s how it works in the audiophile world.
With watches, I suspect it’s just a sort of holdover from the days when “Quartz” was a selling point some 45 years ago, and also an indicator of a minimum quality standard- i.e. your cheap watch is at least a cheap quartz watch instead of somethign else entirely.
Most people probably don’t really know what it means anyway- and those who do probably wouldn’t know how to interpret the absence of “Quartz” on a cheap watch. I mean, I’d wonder if it was some particularly terrible mechanical piece of Chinesium, or if it was just an unlabeled quartz watch (my default assumption).
I was all primed to ask what the advantage of a hybrid watch was. It sounded like trying to invent an automobile by designing a mechanical horse to pull your carriage.
Such were built pre-1900, hopefully to trick real horses into calmness. Didn’t work, not with noisy internal combustion engines. Should have gone electric.