Yippity, I have what most would call a cheap cnc. It's just a FoxAlien Masataur with an upgraded 300W spindle. It comes in around $600-$700 and is considered a hobby unit. I've only had it about a month and still learning what it can do. Last night I was able to engrave and cut 1/8" aluminum for a friend, but I had to slow way down from what I expected to be able to do. I'm also a jeweler. I think it would probably work using diamond burrs that you would usually use at the jewelry bench. Since aluminum is around 2.75 and quartz is up around 7 on the mohs it will probably be very slow though. I'll look around my shop and see if I have a piece of quartz bug enough to work with and give it a try. I'll let you know how it goes. This could be fun.