These two photos are camera shots from separate geological sites. They may help us to understand why chunks of quartz (or quartzite) are commonly found in so many local fields. In fact, beginning students in earth science classes soon learn that most of their collected rock specimens are various-colored forms of quartz and do not represent different rock types. Reddish or yellowish fissure stains within milky-colored quartz chunks can cause separate chunks to have a completely different appearance.
In the photo on the left the embedded quartz vein in the gneissic rock is still intact. In contrast, the photo on the right shows quartz veins exposed by the decomposition of most any kind of surrounding mother rock that is changing to soil. Considering that quartz (or quartzite) is very resistant to weathering, we should perhaps understand why so many quartz-chunk “rocks” are found scattered in our fields and creek washouts.
Copyright © 2003 William T. Hathaway.