23 May 2011
Whilst physically training for our Rockies course by hiking Signal Knob over the weekend, my student Sherry found this tidy little doubly-terminated quartz crystal:
Isn’t that just adorable?
And also, a bit weird. I’m used to seeing stuff like this in the Piedmont or the Blue Ridge basement complex, but Signal Knob is held up by Silurian quartz sandstones of the Massanutten Formation, and my best guess for the formation of this euhedral quartz crystal is that there was a vein or vug that opened up somewhere in the sandstone, and this little fellow formed in the solution that filled that cavity.
I guess there’s plenty of quartz available, so why not?
There were some dark inclusions trapped inside, but I’ll never be able to tell you what they were, as the crystal dropped out of Sherry’s pack later in the hike. I’m glad that we at least snapped a couple of pictures of it before it was lost to the quartz wilderness again…