Billietite

{{Short description|Uncommon mineral of uranium that contains barium}}

{{Infobox mineral

| name = Billietite

| image = Becquerelite-Billietite-rad08-04c.jpg

| imagesize = 260px

| alt =

| caption = Becquerelite (yellow) and billietite (orange)

| category = Oxide minerals

| formula = Ba(UO₂)₆O₄(OH)₆•8H₂O

| IMAsymbol=Bil{{Cite journal|last=Warr|first=L.N.|date=2021|title=IMA–CNMNC approved mineral symbols|journal=Mineralogical Magazine|volume=85|issue=3|pages=291–320|doi=10.1180/mgm.2021.43|bibcode=2021MinM...85..291W|s2cid=235729616|doi-access=free}}

| molweight =

| strunz = 4.GB.10

| dana = 5.7.1.3

| system = Orthorhombic

| class = Pyramidal (mm2)
(same H-M symbol)

| symmetry = Pbn2₁

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| color = Yellow to golden-yellow, amber-yellow, orange-yellow

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| cleavage = Perfect on {001}, imperfect on {110} and {010}

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| tenacity = Brittle

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| luster = Adamantine

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| diaphaneity = Transparent, translucent

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| density = 5.28 - 5.36 g/cm³

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| other = 25px Radioactive

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| references = [https://www.mineralienatlas.de/lexikon/index.php/MineralData?mineral=Billietite Mineralienatlas][http://www.mindat.org/min-674.html Mindat.org - Billietite]

}}

Billietite is an uncommon mineral of uranium that contains barium. It has the chemical formula: Ba(UO₂)₆O₄(OH)₆•8H₂O. It usually occurs as clear yellow orthorhombic crystals.M. Katherine Pagoaga, Daniel E, Appleman, & James M. Stewart "Crystal structures and crystal chemistry of the uranyl oxide hydrates becquerelite, billietite, and protasite" American Mineralogist, Volume 72, pages 1230-1238, 1987 [http://www.minsocam.org/ammin/AM72/AM72_1230.pdf]

Billietite is named after Valere Louis Billiet (1903–1945), Belgian crystallographer at the University of Ghent, Ghent, Belgium.

Billietite was discovered in the locality of the Shinkolobwe uranium mine in the Haut-Katanga Province of the Democratic Republic of the Congo (DRC).