Editing Quartz (section)

=== Dumortierite quartz ===
Inclusions of the mineral [[dumortierite]] within quartz pieces often result in silky-appearing splotches with a blue hue. Shades of purple or gray sometimes also are present. "Dumortierite quartz" (sometimes called "blue quartz") will sometimes feature contrasting light and dark color zones across the material.<ref name=Cally/><ref name=gemstone>{{cite web | url=http://www.minerals.net/gemstone/dumortierite_gemstone.aspx | title=The Gemstone Dumortierite | publisher=Minerals.net | access-date=23 April 2017 | archive-url=https://web.archive.org/web/20170506074639/http://www.minerals.net/gemstone/dumortierite_gemstone.aspx | archive-date=6 May 2017 | url-status=live | df=dmy-all }}</ref> "Blue quartz" is a minor gemstone.<ref name=Cally>{{cite book|title=Firefly Guide to Gems|first=Cally|last=Oldershaw|publisher=Firefly Books|date=2003|isbn=9781552978146|url=https://archive.org/details/fireflyguidetoge0000olde|url-access=registration|pages=[https://archive.org/details/fireflyguidetoge0000olde/page/100 100]|access-date=19 February 2017}}</ref><ref>{{cite web |last1=Friedman |first1=Herschel |title=THE GEMSTONE DUMORTIERITE |url=https://www.minerals.net/gemstone/dumortierite_gemstone.aspx |website=Minerals.net |access-date=28 November 2020}}</ref>