Metanováčekite

Mg(UO2)2(AsO4)2 · 8H2O
IMA status
  • Approved
IMA symbol
Mnvč
Also known as
  • Metanováčekiet

Where it forms, where it's found

Type locality
Anton Mine
  1. Heubach Valley
  2. Wittichen
  3. Schenkenzell
  4. Rottweil
  5. Freiburg Region
  6. Baden-Württemberg
  7. Germany

48.3289°, 8.3233°

28recorded occurrences
Source · OpenStreetMap

Radioactivity

Physical

Hardness
123456789102.5/ 10 MOHS
  1. 1Talc
  2. 2Gypsum
  3. 3Calcite
  4. 4Fluorite
  5. 5Apatite
  6. 6Orthoclase
  7. 7Quartz
  8. 8Topaz
  9. 9Corundum
  10. 10Diamond
Colour
yellow
Streak
yellowish white
Cleavage
Perfect

Optical

Optical type
Uniaxial (-)
Refractive index
1.595 – 1.632
Surface relief
Moderate
Principal indices
nω 1.632 · nε 1.595
Michel-Lévy diagramhighlighted lineδ = 0.0370
Attainable Michel-Lévy rangeΔ ∈ [0, t·δmax]370 nm1st order
Δ = 0Δmax
Thin-section mosaic70 grains · random 3D orientations
PPLpleochroism per grain
XPLindependent extinctions · rotate the stage
Interference simulatorsingle grain · PPL ↔ XPL
PPLpleochroism only · colour blends on rotation
XPLinterference colour · extinct every 90°
Retardation370 nm
Order1st order
XPL colour

Crystallography

Crystal system
Tetragonal
Space group
#138
Cell parameters
a = 7.16 Å · c = 8.58 Å
Z
1
Morphology

Tabular.

Comment

Maybe pseudo-tetragonal.

Chemical composition

Constituent elements
Mass composition breakdown
ElementAtoms At. mass g/mol Mass g/molMass share
92UUraniumUranium2238.029476.058
48.27%
8OOxygenOxygen2015.999319.980
32.44%
33AsArsenicArsenic274.922149.844
15.19%
12MgMagnesiumMagnesium124.30524.305
2.46%
1HHydrogenHydrogen161.00816.128
1.64%
Total986.315100.00%

Mass share = atoms × atomic mass ÷ molar mass × 100

From IMA formula

Synonyms

  • Metanováčekiet

In other languages

German
Metanováčekit
Italian
Metanováčekite

Classification

Strunz
10th ed.

8.EB.10

  • 8Phosphates, Arsenates, VanadatesClass
  • 8.EUranyl phosphates and arsenatesDivision
  • 8.EBUO2:RO4 = 1:1Group
  • 8.EB.10MetanováčekiteSpecies
Dana
8th ed.

40.2a.10.02

  • 40Hydrated Normal Phosphates, Arsenates and VanadatesClass
  • 40.2aAB2(XO4)2·xH2O, containing (UO2)2+Type
  • 40.2a.10— unnamed intermediate level —Group
  • 40.2a.10.02MetanováčekiteSpecies
CIM

20.7.6

  • 20Arsenates (also arsenates with phosphate, but without other anions)Class
  • 20.7Arsenates of UGroup
  • 20.7.6MetanováčekiteSpecies

Group, growth & confusion

Often grow together
1 mineral

Literature, links & citation

Citations
  1. 1951Frondel, Clifford (1951) Studies of uranium minerals (IX): Saléeite and novacekite. American Mineralogist, 36 (9-10) 680-686
  2. 1955Donnay, G., Donnay, J.D.H. (1955) Contribution to the crystallography of uranium minerals. in Contribution to the Crystallography of Uranium Minerals, Geological Survey for the United States Atomic Energy Commission, Technical Information Service (Oak Ridge): 1-42.
  3. 1958Walenta, Kurt (1958) Die sekundären Uranmineralien des Schwarzwaldes. Jahreshefte des geologischen Landesamtes in Baden-Württemberg: 3: 17-51.
  4. 1961Walenta, K., Wimmenauer, W. (1961) Der Mineralbestand des Michaelganges im Weiler bei Lahr (Schwarzwald). Jahreshefte des Geologischen Landesamts Baden-Württemberg: 4: 7-37 (in German).
  5. 1964Walenta, Kurt, Walenta, Kurt (1964) Beiträge zur Kenntnis seltener Arsenatmineralien unter besonderer Berücksichtigung von Vorkommen des Schwarzwaldes. 1. Folge. [Rare arsenate minerals with special consideration of occurrences in the Black Forest. Part I]. Tschermaks Mineralogische und Petrographische Mitteilungen, 9 (1). 111-174 doi:10.1007/bf01127780DOI: 10.1007/bf01127780
Cite this entry
@misc{mineral2026,
  author    = {Mineral Index editorial board},
  title     = {Metanováčekite — Mineral Index},
  year      = {2026},
  url       = {https://mineralindex.org/minerals/metanovacekite-2681},
  note      = {Accessed 2026-05-11}
}