Dendrites are often confused with fossils.  Dendrites are crystalline features with a branching treelike structure formed when mineral rich water seeps into sedimentary stones.  The examples here are in the Lyons sandstone that I use on most of my table tops.

When I found these very thin slabs of dendritic sandstone at the Western Stone yard in Lyons in 2012 they were not unusual.  Since then the good dendtritic stones are 'high graded' and sold before they go to the stone yard for sale. Below you can see a good view of the dendritic features.

The rim is a used whiskey barell hoop. No I didn't empty the barell to get the hoop. I should have. My local hardware store, McGukins, in Boulder stopped stocking hairpin legs, so I had to buy these from hairpinlegs.com.  

I made and gifted this table before I started selling on ETSY.   

I'd love to make a table for you.