Rough concept of what I am talking about. The Quartz counter top is made of 93% quartz and 7% binder. It is pressed and heat treated for high strength. The size of pieces that I would use are all available in the remnant area for about 10$ a square foot. I would use inserted nuts for clamping and jack screws and then fill the gap between pieces with epoxy so that all dimensions could be as accurate as possible.