There are piezo actuators you could certainly feel but not sure they are made of quartz, maybe PZT.

You mean could you get it down to a low enough frequency? Hmm I guess you can get down into audio frequency but maybe the amplitude will be tiny, you probably want a piezo mechanism that will give you more of a rumble.

You can get quartz to resonate down to upper audio frequencies with certain crystal cuts and manufacturing techniques but it's difficult. Typically, the lowest frequency in common use is with its use in watches with a frequency of 32,768Hz (that's about the lower limit where manufacturing and frequency combine to make a useful product).

For electronic circuits such as frequency reference markers where frequency stability is important the lowest practical frequency is 100kHz with 1Mhz preferred, and where frequency tolerances are tight 5 and 10MHz are much preferred with operation in a temperature stabilized oven to minimize frequency drift.

The most frequency-stable crystal cuts are at those frequencies, as frequencies increase (say >10MHz to 100MHz), which at the highest frequencies require the crystal to operate in overtone mode, frequency stability again tends to decrease.

As mentioned in the article there are a lot of common watch crystals that oscillate at 32.768 kHz, but they are tuning fork crystals rather than bulk mode (or modern SAW), which have much higher frequencies. It would be challenging to lower the frequency of these, but perhaps you could evaporate Au or W onto the tips and reseal them to get into the audible frequencies. Much easier would be to get two crystals which beat against each other in the audio range. Even a couple of 6MHz crystals 100ppm off would be ~6kHz (temp sensitive), and you would need some driving circuits, but you might be able to hear the beat by driving an electret microphone or a really tiny tweeter coil speaker (probably need an amp though).

It's much easier to build/buy electrical rather than mechanical LC components to hit audio frequencies ~100Hz-10kHz.

There are piezo buzzers and beepers, of course.

Yes, but those normally just convert the electrical oscillations to sounds, they are not parts of the oscillators that determine the audible frequency.

In the past, audio RC oscillators or LC oscillators were used, with the former being preferred as the latter required too bulky inductors to reach so low frequencies.

Nowadays, it is usually simpler to not use any audio oscillator, but to use some microcontroller that divides the frequency of its clock until reaching the desired audio frequency.

Those can make sounds at other frequencies but they are very loud on their resonant frequency. Loud enough to damage your hearing if you're unlucky.

And a similar question: if you took a normal magnet and rotated it very quickly, say 10k rpm, would it emit an RF signal at (10k/60) hz? I'm 95% sure the answer is yes but I've never seen this demonstrated.