Mount Rodgers rhyolite, 44GY0018, Grayson County, Virginia.
This sample of Mount Rogers rhyolite was recovered from site 44GY0018, Grayson County, Virginia.
This meta-rhyolite ranges in color from a gray to purple with phenocrysts of white or pink, depending on their mineral composition. The rhyolite is typically fine-grained or aphanitic in texture, but some specimens show a granular texture. Phenocrysts, in excess of 5 mm in diameter, can constitute as much as 40% of the rock. Metamorphosis has advanced to the stage where the rock flakes across the phenocrysts, reacting as if they were not present.
Mount Rogers rhyolite does not appear to have traveled far from its source in Grayson County, Virginia
The utilization of Mount Rogers rhyolite may have begun as early as the Early Archaic. Its greatest use was during the Middle and Late Archaic periods and continued into the Woodland Period.
Prepared By Tolley 1999