Phosphuranylite(H3 O)3 KCa(UO2 )7 O4 (PO4 )4 • 8H2 O
c 2001-2005 Mineral Data Publishing, version 1

Crystal Data: Orthorhombic. Point Group: 2/m 2/m 2/m. In thin scales, irregular torectangular in outline, to 2 mm. Commonly as scaly crusts, thin films, and coatings.
Physical Properties:
Cleavage: One, perfect, k flattening.
D(meas.) = ∼4.1 D(calc.) = 4.575–4.631 Radioactive.

Hardness = 2–2.5

Optical Properties: Semitransparent. Color: Deep golden yellow, lemon-yellow,
honey-yellow.
Optical Class: Biaxial (–), commonly nearly uniaxial (–). Pleochroism: X = colorless; Y = Z =golden yellow. Orientation: Z ⊥ flattening. Dispersion: r > v, strong. Absorption: X < Y =Z; may be X < Y < Z. α = 1.658–1.695 β = 1.699–1.77 γ = 1.699–1.77 2V(meas.) = 0◦ –35◦
Cell Data: Space Group: Cmcm. a = 15.779–15.899
c = 17.253–17.330 Z = 4

b = 13.702–13.790

X-ray Powder Pattern: Flat Rock mine, North Carolina, USA; nearly identical todewindtite.
7.83 (10), 3.969 (9), 5.829 (8), 3.363 (6), 3.121 (6), 2.858 (6), 1.895 (5)Chemistry:
UO3
P2 O5PbO

(1)
76.4
11.1
trace

(2)
78.1
10.3
0.2

(3)
76.58
10.86

CaO
K2 O
H2 O

(1)
2.3
n.d.
n.d.

(2)
2.1
2.5
[6.8]

(3)
2.15
1.80
8.61

Total
[100.0]100.00(1) Rosmaneira, Portugal; partial analysis. (2) Bois Noirs, France; by electron microprobe, H2 O
by difference. (3) (H3 O)3 KCa(UO2 )7 O4 (PO4 )4 • 8H2 O.
Occurrence: A secondary mineral typically occurring in the weathering zone of granite
pegmatites, coating cracks and fissures near altered uraninite; in paleochannels in sandstone
Colorado Plateau-type U–V deposits.
Association: Uraninite, autunite, meta-autunite, uranophane, uranophane-beta, becquerelite,curite, parsonsite, torbernite, metatorbernite, saléeite, sabugalite, haiweeite, uranian “opal”.
Distribution: In the USA, from the Flat Rock and Buchanan pegmatite mines, Mitchell Co.,
North Carolina; in the Ruggles mine, near Grafton, and the Palermo #1 mine, near North
Groton, Grafton Co., New Hampshire; at Newry, Oxford Co., Maine; from Branchville, FairfieldCo., Connecticut; at the Barker (Ferguson) mine, five km southeast of Keystone, Pennington Co.,South Dakota; from the DeLongchamps and Red Bluff mines, Pyramid district, Washoe Co., andseveral other occurrences in Nevada. In Brazil, at the Énio and Córrego do Urucum pegmatites,
near Galiléia, Minas Gerais; in the Perus district, 25 km north of São Paulo. From Pamplonita,Colombia. At Peveragno, Piedmont, and Arcu su Linnarbu, near Capoterra, Cagliari, Sardinia,Italy. From the La Crouzille mine and Margnac mine, Compreignac, Haute-Vienne, and at BoisNoirs, Loire, France. From Wölsendorf, Bavaria, Germany. In Portugal, at Carrasca, Sabugal,Mangualde, and elsewhere. From Shinkolobwe, Katanga (Shaba) Province, and at the Kobokobo
pegmatite, Lusungu River district, Kivu Province, Congo (Zaire). At Vatovory, Madagascar. In
the Saddle Ridge mine, South Alligator Valley, Northern Territory, Australia. Known from anumber of other minor localities.
Name:

For phosphorus and uranyl uranium in the composition.

Type Material: Pennsylvania State University, State College, Pennsylvania; Yale University,New Haven, Connecticut, USA, 3249–3251.
References: (1) Palache, C., H. Berman, and C. Frondel (1951) Dana’s system of mineralogy,(7th edition), v. II, 876. (2) Frondel, C. (1950) Studies of uranium minerals (V): phosphuranylite.
Amer. Mineral., 35, 756–763. (3) Frondel, C. (1958) Systematic mineralogy of uranium andthorium. U.S. Geol. Sur. Bull. 1064, 222–227. (4) Demartin, F., V. Diella, S. Donzelli, C.M.
Gramaccioli, and T. Pilat (1991) The importance of accurate crystal structure determinationof uranium minerals. I. Phosphuranylite KCa(H3 O)3 (UO2 )7 (PO4 )4 O4 • 8H2 O. Acta Cryst., 47,439–446.
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