Zippeite

K2[(UO2)4(SO4)2O2(OH)2](H2O)4

Crystal Data: Monoclinic, pseudo-orthorhombic. Point Group: 2/m. Rare crystals are rhomboidal orplaty on {010}, elongated along [001], to 0.5 mm; in radial or vermicular aggregates, earthy
efflorescences, powdery coatings, and crusts. Twinning: Probable, observed in synthetic material.
Physical Properties: Hardness = ∼2 D(meas.) = 4.8 D(calc.) = 4.66 Radioactive; commonly
fluoresces yellow-green to green under SW and LW UV.
Optical Properties: Semitransparent. Color: Deep yellow, yellow-orange, red, brownish yellow,brownish orange. Luster: Vitreous.
Optical Class: Biaxial (–) (synthetic). α = 1.625(1) β = 1.710(2) γ = 1.740(2) 2V(meas.) = Large.
2V(calc.) = 59° Pleochroism: X = nearly colorless; Y = pale yellow to yellow-orange; Z = deep
yellow to yellow-orange.
Cell Data: Space Group: C2/m. a = 8.7802(6) b = 13.9903(12) c = 8.8630(6) β = 104.524(7)° Z = 2
X-ray Powder Pattern: Jáchymov, Czech Republic.
7.06 (10), 3.50 (9), 3.12 (8), 2.87 (4), 2.65 (4), 2.22 (4), 5.45 (3)Chemistry:

SO3
SiO2
UO3
FeO
CaO

(1)
10.24
0.51
80.12
0.19
0.09

(1)
CoO
0.07
Na2O
0.03
K2O
5.48
H2O
[6.01]
Total 102.74(1) Jáchymov, Czech Republic; average of 4 electron microprobe analyses, H2O calculated fromstructure and for charge balance; corresponds to (K1.73Fe0.04Ca0.02Na0.02Co0.01)Σ=1.82[(UO2)4.16O2(OH)1.91(SO4)1.90(SiO4)0.13]Σ=2.03](H2O)4.
Occurrence: An uncommon secondary mineral, in part post-mine, in oxidized uranium deposits.
Association: Uranopilite, natrozippeite, nickelzippeite, magnesiozippeite, johannite, uranophane,schröckingerite, gypsum.
Distribution: From Jáchymov (Joachimsthal), Czech Republic. At Nowa Ruda, Lower Silesia,
Poland. In England, from Cornwall, at the Gunnislake mine, Calstock; the South Terras mine, St.
Stephen-in-Brannel; the Carharrack mine, St. Day; Wheal Buller, Redruth; Wheal Edward andWheal Owles, St. Just. From the USA, in Colorado, at the Diamond Joe and Remington mines,
Idaho Springs district, Clear Creek Co., and in the Telegraph, Wood, and Kirk mines, Gilpin Co.; atthe Apex mine, Reese River district, Lander Co., Nevada; in Arizona, from the Hillside mine, about
5.5 km north of Bagdad, Eureka district, Yavapai Co., in the Monument No. 1 and Mitten No. 2mines, Navajo Co., and at the Huskon No. 7 and No. 8 claims, and the Sun Valley mine, in theCameron area, Coconino Co. Other localities are probable but require modern confirmation.
Name: Honors Dr. František Xaver Maximillian Zippe (1791-1863), Austrian mineralogist andgeologist.
References: (1) Palache, C., H. Berman, and C. Frondel (1951) Dana’s system of mineralogy, (7thedition), v. II, 598-599. (2) Frondel, C., J. Ito, R.M. Honea, and A.M. Weeks (1976) Mineralogy ofthe zippeite group. Can. Mineral., 14, 429-436. (3) Vochten, R., L. Van Haverbeke, K. Van Springel,
N. Blaton, and O.M. Peeters (1995) The structure and physicochemical characteristics of synthetic
zippeite. Can. Mineral., 33, 1091-1101. (4) Ondruš, P., F. Veselovský, J. Hloušek, R. Skála,I. Vavřín, J. Frўda, J. Cejka, and A. Gabašová (1997) Secondary minerals of the Jáchymov(Joachimsthal) ore district. J. Czech Geol. Soc., 42(4), 3-76, esp. 57-58. (5) Burns, P.C., K.M.
Deely, and L.A. Hayden (2003) The crystal chemistry of the zippeite group. Can. Mineral., 41, 687706. (6) Plášil, J., S.J. Mills, K. Fejfarová, M. Dušek, M. Novák, R. Škoda, J. Čejka, and J. Sejkora(2011) The crystal structure of natural zippeite, K1.85H+0.15[(UO2)4O2(SO4)2(OH)2](H2O)4, fromJáchymov, Czech Republic. Can. Mineral., 49(4), 1089-1103.
Mineralogical Society of America

Handbook of Mineralogy

Revised 2/1/2021