Quartz
silicon dioxide
SiO2
![Amethyst Geode with Agate Shell and a Single Clear Quartz Crystal](http://marulla.com/wp-content/uploads/2008/11/imgp064.jpg)
Amethyst Geode with Agate Shell and a Single Clear Quartz Crystal
Dugway Geode Beds, Utah
Collected on 27 Aug 2006
![Quartz Geode](http://marulla.com/wp-content/uploads/2008/11/imgp078.jpg)
Quartz Geode
Harrodsburg, Indiana
Collected on 11 Sep 2006
![Quartz Stalactite](http://marulla.com/wp-content/uploads/2008/10/0171.jpg)
Quartz Stalactite
Aspen Mine, near Silverton, Colorado
Collected on 5 Oct 2008
![Drusy Quartz on Quartz Crystals](http://marulla.com/wp-content/uploads/2008/10/016.jpg)
Drusy Quartz on Quartz Crystals
Revenue Mine, Ouray, Colorado
Collected on 7 Oct 2008
![Closeup of Drusy Quartz on Quartz Crystals](http://marulla.com/wp-content/uploads/2008/10/017.jpg)
Closeup of Drusy Quartz on Quartz Crystals
Revenue Mine, Ouray, Colorado
Collected on 7 Oct 2008
![Small Quartz Vug](http://marulla.com/wp-content/uploads/2008/10/0141.jpg)
Small Quartz Vug
Crystal Hill Mine, La Garita, Colorado
Collected on 10 Oct 2008
![Closeup of Quartz Geode](http://marulla.com/wp-content/uploads/2009/06/101.jpg)
Closeup of Quartz Geode
Keokuk, Iowa
Collected on 1 Aug 2006