Saturday, March 28, 2009

Blue Quartz from Old Rag Virginia area

A few years ago the Fern Valley staff and volunteers went on a spring field trip to the mountain property of two of the volunteers. We climbed up and down their steep trails and saw excellent spring wildflowers including Trilliums, Saxifrage, and Hepaticas. They were nice enough to let me take this piece of blue quartz. The rock is a beautiful color and reminds me of my childhood; it was common in the fields of my Grandmother's farm near the Albemarle County / Nelson County line on Route 29.

I did some research and found an article about Blue Quartz occurrences in Virginia in Virginia Minerals. They are confined to metamorphosed igneous intrusives of the Grenville Age. The source of the color is not conclusively explained, but either it is caused by multiple aligned micro-fractures that affect the reflectivity of light, or it is caused by the presence of Titanium. Rutile (a Titanium mineral) exists as inclusions in most of the blue quartz, but the blueness of the rock doesn't correlate with the percentage of Rutile?? I'm confused, but I guess it's no more or less beautiful whatever the explanation. I walk past it every day but today it leapt out at me, I guess because I had just seen Debby and Laurie at the Lahr Native Plant Symposium.

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