Schoepite

{{Short description|Mineral}}

{{Infobox mineral

| name = Schoepite

| category = Uranium minerals

| boxwidth =

| image = Schoepite-Rutherfordine-214963.jpg

| imagesize = 260

| alt =

| caption =

| formula = (UO₂)₈O₂(OH)₁₂ • 12(H₂O)

| IMAsymbol = Sho{{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.GA.05

| dana =

| system = Orthorhombic

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

| symmetry = P2₁ca

| unit cell = a = 14.33 Å, b = 16.79 Å
c = 14.73 Å; Z = 4

| color = Amber, lemon- or sulfur yellow

| colour =

| habit = Commonly as tabular equant, to short prismatic crystals; rarely in microcrystalline aggregates

| twinning =

| cleavage = [001] Perfect, [010] indistinct

| fracture =

| tenacity = Brittle

| mohs = 2.5

| luster = Adamantine

| streak = Yellow

| diaphaneity = Transparent to translucent

| gravity = 4.8

| density =

| polish =

| opticalprop = Biaxial (−)

| refractive = n_α = 1.690 n_β = 1.714 n_γ = 1.735

| birefringence = δ = 0.045

| pleochroism = X = almost colorless; Y = Z = lemon-yellow to golden yellow

| 2V = Measured: 89°

| dispersion =

| extinction =

| length fast/slow =

| fluorescence= Short and long UV = pale green

| absorption =

| melt =

| fusibility =

| diagnostic =

| solubility =

| other = 25px Radioactive

| alteration =

| references = [http://rruff.geo.arizona.edu/doclib/hom/schoepite.pdf Handbook of Mineralogy]

}}

Schoepite, empirical formula (UO₂)₈O₂(OH)₁₂·12(H₂O)[http://www.mindat.org/min-3574.html Mindat.org] is a rare alteration product of uraninite in hydrothermal uranium deposits. It may also form directly from ianthinite. The mineral presents as a transparent to translucent yellow, lemon yellow, brownish yellow, or amber orthorhombic tabular crystals. Although over 20 other crystal forms have been noted; rarely in microcrystalline aggregates. When exposed to air schoepite converts over a short time to the metaschoepite form (UO₃·{{mvar|n}}H₂O, {{math|n < 2}}) within a few months of being exposed to ambient air.[http://www.mindat.org/min-3574.html Mindat.org]

The hardness is 2.5, density is 4.8 g/cm³, and it streaks yellow.

It was first described from specimens from Shinkolobwe mine in Belgian Congo in 1923, several additional localities are known.

Schoepite was named to honor Alfred Schoep (1881–1966), Professor of Mineralogy at the University of Ghent, Belgium.[http://webmineral.com/data/Schoepite.shtml Webmineral data]