Editing Rhyolite (section)

==Uses==
In [[Pre-Columbian era|North American pre-historic times]], rhyolite was quarried extensively in what is now eastern [[Pennsylvania]].  Among the leading quarries was the [[Carbaugh Run Rhyolite Quarry Site]] in [[Adams County, Pennsylvania|Adams County]]. Rhyolite was mined there starting 11,500 years ago.<ref name=Fergus>{{cite book|title=Natural Pennsylvania: Exploring the State Forest Natural Areas|first=Charles|last=Fergus|publisher=Stackpole Books|year=2001|page=30|oclc=47018498}}</ref> Tons of rhyolite were traded across the [[Delmarva Peninsula]],<ref name=Fergus/> because the rhyolite kept a sharp point when [[knapping|knapped]] and was used to make spear points and arrowheads.<ref>{{cite web|title=Snaggy Ridge Indian Rhyolite Quarries|first=Dakota|last=Bricker|publisher=Mercersburg Historical Society|url=http://mhs.mercersburg.org/blog/7/|access-date=2019-01-20}}</ref>

Obsidian is usually of rhyolitic composition, and it has been used for tools since prehistoric times.<ref>{{cite book|author1=Cotterell, Brian |author2=Kamminga, Johan |title=Mechanics of pre-industrial technology: an introduction to the mechanics of ancient and traditional material culture|url=https://books.google.com/books?id=0-xOM8y6Uc8C&pg=PA127|access-date=9 September 2011|year=1992|publisher=Cambridge University Press|isbn=978-0-521-42871-2|pages=127–}}</ref> Obsidian scalpels have been investigated for use in delicate surgery.<ref name=obsidian1>{{cite journal |last = Buck |first = BA|date=March 1982|title = Ancient Technology in Contemporary Surgery|journal = The Western Journal of Medicine|volume = 136|issue = 3|pages = 265–269|pmid= 7046256|pmc = 1273673}}</ref> Pumice, also typically of rhyolitic composition, finds important uses as an [[abrasive]], in [[concrete]],<ref>{{cite book |last1=Grasser |first1=Klaus |title=Building with Pumice |pages=64|isbn= 3-528-02055-5 |date=1990|publisher= Deutsche Gesellschaft für Technische Zusammenarbeit (GTZ) |url=https://www.humanitarianlibrary.org/sites/default/files/2014/02/GATE_buildingWithPumice.pdf |access-date=23 March 2019}}</ref> and as a [[soil amendment]].<ref name="usgs pumice">{{cite web |last1=Crangle |first1=Robert D. Jr. |title=Pumice and pumicite – USGS Mineral Resources Program |url=https://minerals.usgs.gov/minerals/pubs/commodity/pumice/mcs-2012-pumic.pdf |publisher=United States Geological Survey |access-date=25 November 2018 |date=January 2012}}</ref> Rhyolitic tuff was used extensively for construction in ancient Rome<ref name="jackson-etal-2005">{{cite journal |last1=Jackson |first1=M. D. |last2=Marra |first2=F. |last3=Hay |first3=R. L. |last4=Cawood |first4=C. |last5=Winkler |first5=E. M. |title=The Judicious Selection and Preservation of Tuff and Travertine Building Stone in Ancient Rome* |journal=Archaeometry |date=2005 |volume=47 |issue=3 |pages=485–510 |doi=10.1111/j.1475-4754.2005.00215.x|doi-access=free |bibcode=2005Archa..47..485J }}</ref> and has been used in construction in modern Europe.<ref name="schmincke-2003"/>{{rp|138}}