Berryessa Jasper Ring

Here we have a sterling silver arrow ring featuring a triangular cabochon of Berryessa Jasper from Napa County, California.

We collected this material on the western bank of Lake Berryessa, which exhibits some really wild geology. This jasper is known as a brecciated jasper, or a jaspagate colloquially. Earthquakes broke this jasper apart, and filled it with cracks, then silica-rich water filled those cracks and healed them by turning into agate.