Quartz.....

Quartz on a concrete step makes up a good contrasting photo of textures. It was unplanned but did work out great as a good background for my rock.
 

The previous owners had to move out and dumped their rocks into the front yard's rock garden  The rocks are totally different than the river bed rocks and I keep finding them working to the top. The quartz one is not unusual in Iowa but the size and color is so good that I think it must have been in a fountain display that they tossed.  Our quartz shows up in our river rocks but aren't two inches long or less.