Editing Niter (section)

== Characteristics ==
Niter is a colorless to white mineral crystallizing in the [[orthorhombic]] [[crystal system]]. It is the mineral form of [[potassium nitrate]], {{chem2|KNO3}},<ref name=Jackson/> and is soft ([[Mohs hardness]] 2),<ref name="HoM"/> highly soluble in water,<ref name=Jackson>{{cite book |editor1-last=Jackson |editor1-first=Julia A. |title=Glossary of geology. |date=1997 |publisher=American Geological Institute |location=Alexandria, Virginia |isbn=0922152349 |edition=Fourth |chapter=niter}}</ref> and easily fusible. Its crystal structure resembles that of [[aragonite]], with potassium replacing calcium and nitrate replacing carbonate.<ref>{{cite book |last1=Klein |first1=Cornelis |last2=Hurlbut |first2=Cornelius S. Jr. |title=Manual of mineralogy : (after James D. Dana) |date=1993 |publisher=Wiley |location=New York |isbn=047157452X |edition=21st |page=418}}</ref> It occurs in the soils of arid regions and as massive encrustations and [[efflorescent]] growths on [[cave]]rn walls and ceilings where solutions containing [[alkali]] potassium and nitrate seep into the openings.<ref name=Jackson/> It occasionally occurs as prismatic [[Acicular (crystal habit)|acicular]] crystal groups, and individual crystals commonly show pseudohexagonal [[crystal twinning|twinning]] on [110]. Niter and other nitrates can also form in association with deposits of [[guano]] and similar organic materials.<ref name="HoM">{{cite web |last1=Anthony |first1=John W. |last2=Bideaux |first2=Richard A. |last3=Bladh |first3=Kenneth W. |last4=Nichols |first4=Monte C. |title=Niter |url=http://www.handbookofmineralogy.org/pdfs/niter.pdf |website=Handbook of Mineralogy |publisher=Mineral Data Publishing |access-date=28 December 2021 |date=2005}}</ref>