Do you own a quartz watch or a wind up watch?
Not a whole heck of a lot. It's the most abundant mineral on earth, and you can find it just about anywhere. If you've got some nice, undamaged crystals of a decent size, they might be worth something (I've seen them for a couple hundred dollars for the really big ones), but other than that, quartz is pretty common.
Quartz is a very common mineral, which can be worth a little money if they are good quality. Quartz comes in many varieties. Amethyst, Citrine, Smoky quartz, and Rose Quartz are some of the semiprecious gemstone quality varieties of quartz. Also, there are many people out there who will believe anything, including that quartz crystals contain metaphysical properties and will purchase quartz crystals for hundreds of dollars on the promise of some cure or enlightenment. Of course there are people out there trying to trick people into purchasing these crystals for such inflated prices. The vast majority all quartz crystals are of poor quality and are worth little or nothing,