An iconic Colorado semi-precious stone is Sowbelly Agate from the mines nerar Creede.  These stones, according to geoligist friends of mine, feature banded, translucent purple amethyst and white chalcedony with sometimes dendritic native silver.  My cousin, the rock shop owner, turned me on to these stones and gave me some.  So far the table above is the only one I've made using these stones. 

My son and his family have the table, which is one of the few I have put on recycled restaurant table bases.  

The picture above doesn't really show off the stone. Take a look at the image below.

I don't have any sowbelley agate with silver, but I do have a supply of these slabs that I can work into a table top for you....on a recycled restaurant table base, hairpin legs, or some other base of your choice.