Stones and Silver with C-Beam

Hello everybody,

I'm new to this actually, been looking around for a very long time, haven't used a cnc machine before, although I know the concept and I'm building one myself at the moment for the sake of learning.

I'm in the process of buying one myself, however, I'm between choices, and to be honest, only two of them pulled my attention so far, the C-Beam is one of them, I have few questions though:

1. The size of the provided bundle (the working area) is pretty small, that is (13.5" x 11"). I looked around but couldn't figure out if it can be bigger than this.
   
   
2. I'm amazed by the way it handles milling aluminum. My question is, can I use this machine to work with silver as well?
   
   
3. Can I use this machine to work with Gemstones?
   
   
4. I work with electronics, I design PCBs, so can I use this machine to draw the traces on a PCB?

Your help will be much appreciated..

Many thanks in advance..