Becquerelite

{{Short description|Uranium mineral}}

{{infobox mineral

| name = Becquerelite

| image = Becquerelite-Uranophane-Uraninite-201144.jpg

| alt =

| caption = Spray of becquerelite crystals with uranophane needles from the old Shinkolobwe mine

| category = Oxide mineral

| formula = Ca(UO₂)₆O₄(OH)₆·8(H₂O)

|IMAsymbol=Bqr{{Cite journal|last=Warr|first=L.N.|date=2021|title=IMA–CNMNC approved mineral symbols|url=https://www.cambridge.org/core/journals/mineralogical-magazine/article/imacnmnc-approved-mineral-symbols/62311F45ED37831D78603C6E6B25EE0A|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 =

| system = Orthorhombic

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

| symmetry = Pn2₁a

| unit cell = a = 13.8378 Å,
b = 12.3781 Å,
c = 14.9238 Å; Z = 4

| color =

| colour = Amber-yellow, golden to lemon-yellow, yellow-orange, brownish yellow

| habit = Tabular prismatic striated crystals exhibiting pseudohexagonal outline; coatings and fine-grained aggregates

| twinning =

| cleavage = Perfect on {001}; imperfect on {101}, {010} and {110}

| fracture =

| tenacity = Brittle

| mohs = 2.5

| lustre = Adamantine to greasy

| streak = Yellow

| diaphaneity = Transparent

| gravity = 5.09–5.2

| density =

| polish =

| opticalprop = Biaxial (−)

| refractive = n_α = 1.725 – 1.735 n_β = 1.815 – 1.825 n_γ = 1.825 – 1.830

| birefringence = δ = 0.100

| pleochroism = X = colourless to pale yellow, Y = Z = yellow to deep yellow

| 2V = Measured: 32°

| dispersion =

| extinction =

| length fast/slow =

| fluorescence =

| absorption =

| melt =

| fusibility =

| diagnostic =

| solubility =

| impurities = Commonly contains lead

| alteration =

| other = 25px Radioactive

| references = [http://rruff.geo.arizona.edu/doclib/hom/becquerelite.pdf Handbook of Mineralogy][http://www.mindat.org/min-597.html Mindat.org][http://www.webmineral.com/data/Becquerelite.shtml Webmineral data]

}}

Becquerelite is a uranium mineral with the chemical formula: Ca(UO₂)₆O₄(OH)₆·8(H₂O). It is a secondary mineral which contains calcium and is a bright yellow colour. It has a Mohs hardness of about 2.

It was named after the French physicist Antoine Henri Becquerel (1852–1908), who discovered radioactivity in 1896. Becquerelite contains about 70% uranium by weight.

It is mainly mined in Kasolo of the former Zaire, in the present day Democratic Republic of the Congo.