Editing Sphalerite (section)

==Varieties==
Gemmy, colorless to pale green sphalerite from [[Franklin, New Jersey]] (see [[Franklin Furnace]]), are highly fluorescent orange and/or blue under longwave ultraviolet light and are known as ''cleiophane'', an almost pure ZnS variety.<ref name="Manutchehr-Danai-2009">{{Cite book|last=Manutchehr-Danai|first=Mohsen|url=https://www.worldcat.org/oclc/646793373|title=Dictionary of gems and gemology|publisher=Springer-Verlag, Berlin, Heidelberg|year=2009|isbn=9783540727958|edition=3rd|location=New York|pages=|oclc=646793373}}</ref> Cleiophane contains less than 0.1% of iron in the sphalerite crystal structure.<ref name="Cook-2003" /> Marmatite or christophite is an opaque black variety of sphalerite and its coloring is due to high quantities of iron, which can reach up to 25%; marmatite is named after [[Marmato, Caldas|Marmato]] mining district in [[Colombia]] and christophite is named for the St. Christoph mine in [[Breitenbrunn, Saxony|Breitenbrunn]], [[Saxony]].<ref name="Manutchehr-Danai-2009" /> Both marmatite and cleiophane are not recognized by the [[International Mineralogical Association]] (IMA).<ref>{{Cite web|title=International Mineralogical Association – Commission on New Minerals, Nomenclature and Classification|url=http://cnmnc.main.jp/|access-date=2021-02-25|website=cnmnc.main.jp}}</ref> Red, orange or brownish-red sphalerite is termed ruby blende or ruby zinc, whereas dark colored sphalerite is termed black-jack.<ref name="Manutchehr-Danai-2009" />