Where it forms, where it's found
- Geological setting
Post-mining efflorescences on mine walls.
An uncommon secondary mineral, formed in the oxidized zone of uranium-bearing hydrothermal polymetallic deposits; may be post-mine, coating walls of mine tunnels.
- Type locality
- Hillside Mine
- Bozarth Mesa
- Bagdad
- Eureka Mining District
- Yavapai County
- Arizona
- USA
34.6328°, -113.2097°
48recorded occurrences
Radioactivity
Physical
- Hardness
- 1Talc
- 2Gypsum
- 3Calcite
- 4Fluorite
- 5Apatite
- 6Orthoclase
- 7Quartz
- 8Topaz
- 9Corundum
- 10Diamond
- Lustre
- Vitreous
- Transparency
- Transparent · Translucent
- Colour
- Bright green to yellow-green.
- Density
- 2.8 g/cm³
Optical
- Optical type
- Uniaxial (+)
- Refractive index
- 1.52 – 1.54
- Surface relief
- Moderate
- Principal indices
- nω 1.52 · nε 1.54
- Pleochroism
- Visible
O = colourless E = Light yellow
- UV response
- Bright pastel green (a unique color)(SW and LW UV).
Δ = 0Δmax
PPLpleochroism per grain
XPLindependent extinctions · rotate the stage
PPLpleochroism only · colour blends on rotation
XPLinterference colour · extinct every 90°
Retardation200 nm
Order1st order
XPL colour
Crystallography
- Space group
- #80
- Cell parameters
- a = 18 Å · c = 23.83 Å
- Morphology
As rhombohedra, pseudocubic or flattened and with complex form development, to 1 cm; typically in crystalline crusts, granular.
Crystal structure
Chemical composition
Synonyms
- Andersoniet
- Andersonitt
In other languages
- French
- Andersonite
- German
- Andersonit
- Spanish
- Andersonita
- Italian
- andersonite
- Chinese
- 碳钠钙铀矿
Classification
Strunz
10th ed.5.ED.30
- 5CarbonatesClass
- 5.EUranyl CarbonatesDivision
- 5.EDUO2:CO3 = 1:3Group
- 5.ED.30AndersoniteSpecies
Dana
8th ed.15.02.05.01
- 15Hydrated Normal CarbonatesClass
- 15.02AmBn(XO3)p·xH2O, with (m+n):p > 1:1Type
- 15.02.05— unnamed intermediate level —Group
- 15.02.05.01AndersoniteSpecies
CIM
—11.11.12
- 11CarbonatesClass
- 11.11Carbonates of Cr and UGroup
- 11.11.12AndersoniteSpecies
Group, growth & confusion
Literature, links & citation
Citations
- 1951Axelrod, Joseph M., Grimaldi, Frank S., Milton, Charles, Murata, and K. J. (1951) The uranium minerals from the Hillside Mine, Yavapai County, Arizona. American Mineralogist, 36 (1-2) 1-22
- 1951Palache, Charles; Berman, Harry; Frondel, Clifford (1951) The System of Mineralogy (7th ed.) Vol. 2 - Halides, Nitrates, Borates, Carbonates, Sulfates, Phosphates, Arsenates, Tungstates, Molybdates, Etc. John Wiley and Sons.
- 1979Urbanec, Zdeněk, Čejka, Jiří (1979) Infrared spectra of liebigite, andersonite, voglite and schroeckingerite. Collection of Czechoslovak Chemical Communications, 44. 10-23 doi:10.1135/cccc19790010DOI: 10.1135/cccc19790010
- 1981Coda, A., Della Giusta, A., Tazzoli, V. (1981) The structure of synthetic andersonite, Na2Ca[UO2(CO3)3]·xH2O (x≃5.6) Acta Crystallographica Section B Structural Crystallography and Crystal Chemistry, 37 (8) 1496-1500 doi:10.1107/s0567740881006432DOI: 10.1107/s0567740881006432
- 1986Mereiter, K. (1986) Neue kristallographische Daten über das Uranmineral Andersonit. Anzeiger Österreichen Akademie der Wissenschaften, Mathematisch-Naturwissenschaftliche Klasse: 123(3): 39-41.
Cite this entry
@misc{mineral2026,
author = {Mineral Index editorial board},
title = {Andersonite — Mineral Index},
year = {2026},
url = {https://mineralindex.org/minerals/andersonite-219},
note = {Accessed 2026-05-11}
}