Genuine and possibly dumb question

Why do watch makers advertise "quartz"?

Is it the name of the movement or the actual mineral? Isn't it like one of the cheapest and most abundant minerals? Why is it worthy of advertising?

I never understood this.

@chu
quartz movement is controlled by the oscillation of a tiny quartz crystal, this is more accurate than mechanical clockwork so it'll probably never need the time adjusted unless the power is cut.