Editing Tourmaline (section)

=== Dravite ===
[[File:Black Dravite, Yinnietherra, Western Australia.jpg|thumb|left|Black dravite on a grey matrix]]

{{em|Dravite}}, also called {{em|brown tourmaline}}, is the sodium magnesium rich tourmaline endmember. Uvite, in comparison, is a calcium magnesium tourmaline. Dravite forms multiple series, with other tourmaline members, including schorl and elbaite.<ref>{{Cite web|title=What is Tourmaline? – GIA|url=https://www.gia.edu/tourmaline}}</ref>

The name ''dravite'' was used for the first time by [[Gustav Tschermak von Seysenegg|Gustav Tschermak]] (1836–1927), Professor of [[Mineralogy]] and [[Petrography]] at the [[University of Vienna]], in his book ''Lehrbuch der Mineralogie'' (published in 1884) for [[magnesium]]-rich (and [[sodium]]-rich) tourmaline from village Dobrova near [[Dravograd|Unterdrauburg]] in the [[Drava]] river area, [[Duchy of Carinthia|Carinthia]], [[Austria-Hungary|Austro-Hungarian Empire]]. Today this tourmaline locality (type locality for dravite) at Dobrova (near [[Dravograd]]), is a part of the [[Slovenia|Republic of Slovenia]].<ref name="Ertl 2007">Ertl, 2007.</ref> Tschermak gave this tourmaline the name dravite, for the Drava river area, which is the district along the Drava River (in German: ''Drau'', in [[Latin]]: ''Drave'') in [[Austria]] and Slovenia. The chemical composition which was given by Tschermak in 1884 for this dravite approximately corresponds to the formula {{chem2|NaMg3(Al,Mg)6B3Si6O27(OH)}}, which is in good agreement (except for the [[hydroxide ion|OH]] content) with the endmember formula of dravite as known today.<ref name="Ertl 2007" />
 
Dravite varieties include the deep green chromium dravite and the vanadium dravite.<ref>{{Cite web|title=Tourmaline Information – Gemstone Education|url=https://www.starlanka.com/gemstone-education/tourmaline-stone/}}</ref>