THE STUFF THAT MAKES YOUR STUFF WORK: Quartz crystal

It’s an exaggeration to say the world runs on quartz, but not much of one. You probably know that quartz has something to do with timing, but it’s probably not clear exactly what. Quartz, like many crystals, has a piezoelectric quality. That is to say, if you put electricity into it, it will distort and return to shape in a very predictable period of time. Most people think that simply applying electricity to quartz will make it vibrate at exactly 60 cycles per second, but it’s actually a little more complex than that. You can make quartz do its little dance at any frequency you want (within reason) actually and the reason people think that 60 is the magic number is that’s the frequency of your typical watch crystal.

Crystals aren’t all quartz, although quartz is easy to manufacture and incredibly stable. It’s used any time precise timing is needed, and that happens to be pretty much any time an electronic component is used. Anything that makes your life better or even more fun has at least one crystal in it, and that includes every TV and radio you’ve ever seen, every computer, every cell phone (if you’re old enough you might have seen a landline phone that didn’t need a crystal), every camera and every electric watch. Life runs on crystals.

This particular quality of crystals was only discovered about 140 years ago and was first used to control the frequency of radio transmissions. Without crystal oscillators, it would be practically impossible to create a tunable radio station; its frequency would jump up and down by 3-4kHz at a whim. Crystals were originally mined from the ground but since about 1950 it’s been possible to grow them synthetically which makes them not only cheaper but also more reliable.

By the late 1960s, quartz crystals were used in the first electronic watches and calculators and the public finally became aware of the stable properties of quartz. It’s not even the most stable crystal but it’s certainly good enough for most consumer uses. The most stable oscillators, by the way, aren’t even crystal. Ceramic resonators are much much more stable and are used to measure molecular decay and for things like setting the clocks used in the national standards institute.

Of course, if you remember the 1970s, you’ll also remember that quartz’s ability to vibrate reliably in the presence of electric fields meant that some folks thought it was a conduit for “human energy” or witchcraft; those properties have yet to be proven.