Rockhounding Thunder Eggs at Richardson’s Rock Ranch

My daughter posing at the trailheadMy five-year-old daughter has been very interested in rocks, crystals, and minerals lately, an offshoot of her intense interest in faeries and the natural realm over which they preside. At her request, I pulled up several images from Google displaying a variety of agates, jasper, geodes and, of course, thunder eggs. This led to a short hike to a nearby creek, after which she discovered several examples of quartz and red agates polished by the stream. By the time this trip had ended, a new pebble puppy was born and my inner rockhound had been reawakened.

We happen to live in a very geologically active area and a perfect breeding ground for all sorts of beautiful minerals awaiting discovery. The Pacific¬†Northwest is home to a family of volcanoes in the Cascade Range. Over millennia they would belch ash rich in silica on to the desert planes. This silica rich volcanic ash, known as ryolite, accumulated and eroded forming striking reddish cliffs that enhance the otherwise monotonous desert landscape. The silica, being water soluble, percolated through the porous rock, eventually settling in gas-evacuated hollow spaces of the hardened basalt. Over time this material solidified, forming the colorful agate centers of what we now call thunder eggs. With such rich geology a stone’s throw away we planned a family trip to mine some eggs and start an epic rock collection. A few rock hammer purchases later and we were on our way. [Read more…]