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Ianthinite

A valid IMA mineral species - grandfathered
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About IanthiniteHide

Formula:
U4+(UO2)5O7 · 10H2O
Colour:
Violet-black; dark violet in transmitted light
Lustre:
Sub-Metallic
Hardness:
2 - 3
Specific Gravity:
5.16
Crystal System:
Orthorhombic
Name:
From the Greek ιάνθινος ("ianthinos"), violet colored, in allusion to its color.
Not very stable under ambient conditions; will dehydrate to schoepite (while becoming yellow and opaque) and further members of the schoepite group.

May be confused with nollmotzite.

Sheets in the crystal structure are similar to those in rameauite, spriggite and wyartite.


Unique IdentifiersHide

Mindat ID:
2000
Long-form identifier:
mindat:1:1:2000:4

IMA Classification of IanthiniteHide

Approved, 'Grandfathered' (first described prior to 1959)
IMA Formula:
U4+2(UO2)4O6(OH)4 · 9H2O
First published:
1926

Classification of IanthiniteHide

4.GA.10

4 : OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodates)
G : Uranyl Hydroxides
A : Without additional cations
Dana 7th ed.:
5.6.1.1
5.6.1.1

5 : OXIDES CONTAINING URANIUM OR THORIUM
6 : AX6O17·xH2O
7.16.7

7 : Oxides and Hydroxides
16 : Oxides of U

Mineral SymbolsHide

As of 2021 there are now IMA–CNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams.

SymbolSourceReference
IanIMA–CNMNCWarr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43

Pronunciation of IanthiniteHide

Pronunciation:
PlayRecorded byCountry
Jolyon RalphUnited Kingdom

Physical Properties of IanthiniteHide

Sub-Metallic
Transparency:
Transparent
Colour:
Violet-black; dark violet in transmitted light
Streak:
Brown, violet
Hardness:
2 - 3 on Mohs scale
Cleavage:
Perfect
Perfect on {001}
Density:
5.16(5) g/cm3 (Measured)    5.00 g/cm3 (Calculated)

Optical Data of IanthiniteHide

Type:
Biaxial (-)
RI values:
nα = 1.674 nβ = 1.900 nγ = 1.920
2V:
Measured: 58° , Calculated: 30°
Max. Birefringence:
δ = 0.246
Based on recorded range of RI values above.

Interference Colours:
The colours simulate birefringence patterns seen in thin section under crossed polars. They do not take into account mineral colouration or opacity.

Michel-Levy Bar The default colours simulate the birefringence range for a 30 µm thin-section thickness. Adjust the slider to simulate a different thickness.

Grain Simulation You can rotate the grain simulation to show how this range might look as you rotated a sample under crossed polars.

Surface Relief:
Moderate
Dispersion:
r > v perceptible
Pleochroism:
Visible
Comments:
X = c = colourless
Y = b = violet
Z = a = dark violet

Chemistry of IanthiniteHide

Mindat Formula:
U4+(UO2)5O7 · 10H2O
Element Weights:
Element% weight
U75.954 %
O22.974 %
H1.072 %

Calculated from ideal end-member formula.

Crystallography of IanthiniteHide

Crystal System:
Orthorhombic
Class (H-M):
mm2 - Pyramidal
Space Group:
Amm2
Cell Parameters:
a = 11.52(5) Å, b = 7.15(2) Å, c = 30.3(1) Å
Ratio:
a:b:c = 1.611 : 1 : 4.238
Unit Cell V:
2,495.75 ų (Calculated from Unit Cell)
Z:
4
Morphology:
Tiny rectangular plates {001} elongated [010]. Also prismatic [010], or thick tabular {001}.

Crystal StructureHide

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IDSpeciesReferenceLinkYearLocalityPressure (GPa)Temp (K)
0013139IanthiniteBurns P C, Finch R J, Hawthorne F C, Miller M L, Ewing R C (1997) The crystal structure of ianthinite, [U4+2(UO2)4O6(OH)4](H2O)5: a possible phase for Pu4+ incorporation during the oxidation of spent nuclear fuel Journal of Nuclear Materials 249 199-2061997Shinkolobwe mine, Shaba, southern Congo0293
CIF Raw Data - click here to close

X-Ray Powder DiffractionHide

Powder Diffraction Data:
d-spacingIntensity
7.63 Å(FF)
3.81 Å(m)
3.24 Å(m)
3.59 Å(fm)
3.35 Å(fm)
2.61 Å(f)
2.53 Å(f)

Geological EnvironmentHide

Paragenetic Mode(s):
Paragenetic ModeEarliest Age (Ga)
Near-surface Processes
27 : Radioactive decay; auto-oxidation
Stage 7: Great Oxidation Event<2.4
47a : [Near-surface hydration of prior minerals]
47f : [Uranyl (U⁶⁺) minerals]

Type Occurrence of IanthiniteHide

Synonyms of IanthiniteHide

Other Language Names for IanthiniteHide

Common AssociatesHide

Associated Minerals Based on Photo Data:
31 photos of Ianthinite associated with Schoepite(UO2)8O2(OH)12 · 12H2O
6 photos of Ianthinite associated with ParauranophaneCa(UO2)2(SiO3OH)2 · 5H2O
4 photos of Ianthinite associated with UraniniteUO2
2 photos of Ianthinite associated with Umohoite(UO2)MoO4 · 2H2O
2 photos of Ianthinite associated with Uranopilite(UO2)6(SO4)O2(OH)6 · 14H2O
2 photos of Ianthinite associated with FourmarieritePb(UO2)4O3(OH)4 · 4H2O
1 photo of Ianthinite associated with CuritePb3(H2O)2[(UO2)4O4(OH)3]2
1 photo of Ianthinite associated with GypsumCaSO4 · 2H2O
1 photo of Ianthinite associated with ArsenuranospathiteAl(UO2)2(AsO4)2F · 20H2O
1 photo of Ianthinite associated with PyriteFeS2

Related Minerals - Strunz-mindat GroupingHide

4.GA.05ParaschoepiteUO3 · 2H2OOrth. mmm (2/m 2/m 2/m) : Pbca
4.GA.05Metaschoepite(UO2)8O2(OH)12 · 10H2OOrth. mmm (2/m 2/m 2/m) : Pbcn
4.GA.05Schoepite(UO2)8O2(OH)12 · 12H2OOrth. mmm (2/m 2/m 2/m) : Pbca
4.GA.15MetastudtiteUO4 · 2H2OOrth. mmm (2/m 2/m 2/m) : Pnma
4.GA.15Studtite[(UO2)(O2)(H2O)2] · H2OMon. 2/m : B2/b
4.GA.20PaulscherreriteUO2(OH)2Mon.
4.GA.25HeisenbergiteUO2(OH) · 2H2O (simplified UO3 · 2H2 O)Orth.

RadioactivityHide

Radioactivity:
Element % Content Activity (Bq/kg) Radiation Type
Uranium (U) 75.9539% 18,988,475 α, β, γ
Thorium (Th) 0.0000% 0 α, β, γ
Potassium (K) 0.0000% 0 β, γ

For comparison:

  • Banana: ~15 Bq per fruit
  • Granite: 1,000–3,000 Bq/kg
  • EU exemption limit: 10,000 Bq/kg

Note: Risk is shown relative to daily recommended maximum exposure to non-background radiation of 1000 µSv/year. Note that natural background radiation averages around 2400 µSv/year so in reality these risks are probably extremely overstated! With infrequent handling and safe storage natural radioactive minerals do not usually pose much risk.

Interactive Simulator:

Note: The mass selector refers to the mass of radioactive mineral present, not the full specimen, also be aware that the matrix may also be radioactive, possibly more radioactive than this mineral!

Activity:

DistanceDose rateRisk
1 cm
10 cm
1 m

The external dose rate (D) from a radioactive mineral is estimated by summing the gamma radiation contributions from its Uranium, Thorium, and Potassium content, disregarding daughter-product which may have a significant effect in some cases (eg 'pitchblende'). This involves multiplying the activity (A, in Bq) of each element by its specific gamma ray constant (Γ), which accounts for its unique gamma emissions. The total unshielded dose at 1 cm is then scaled by the square of the distance (r, in cm) and multiplied by a shielding factor (μshield). This calculation provides a 'worst-case' or 'maximum risk' estimate because it assumes the sample is a point source and entirely neglects any self-shielding where radiation is absorbed within the mineral itself, meaning actual doses will typically be lower. The resulting dose rate (D) is expressed in microsieverts per hour (μSv/h).

D = ((AU × ΓU) + (ATh × ΓTh) + (AK × ΓK)) / r2 × μshield

Other InformationHide

Notes:
Radioactive.
Alters upon heating with dilute hydrogen peroxide, turning brown, then yellow.
Health Risks:
No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.

Internet Links for IanthiniteHide

References for IanthiniteHide

Reference List:

Localities for IanthiniteHide

This map shows a selection of localities that have latitude and longitude coordinates recorded. Click on the symbol to view information about a locality. The symbol next to localities in the list can be used to jump to that position on the map.

Locality ListHide

- This locality has map coordinates listed. - This locality has estimated coordinates. ⓘ - Click for references and further information on this occurrence. ? - Indicates mineral may be doubtful at this locality. - Good crystals or important locality for species. - World class for species or very significant. (TL) - Type Locality for a valid mineral species. (FRL) - First Recorded Locality for everything else (eg varieties). Struck out - Mineral was erroneously reported from this locality. Faded * - Never found at this locality but inferred to have existed at some point in the past (e.g. from pseudomorphs).

All localities listed without proper references should be considered as questionable.
Australia
 
  • Tasmania
    • Northern Midlands municipality
      • Rossarden mining district
Bottrill (2018)
Brazil
 
  • Bahia
Pires et al. (2014)
DR Congo (TL)
 
  • Haut-Katanga
    • Kambove Territory
      • Shinkolobwe
Guillemin et al. (1959) +2 other references
Gauthier et al. (1989)
Egypt
 
  • Red Sea Governorate
Hussein et al. (1988)
France
 
  • Auvergne-Rhône-Alpes
    • Loire
      • Roanne
        • Saint-Priest-la-Prugne
- (1998)
J. Chervet et G. Branche : ... +1 other reference
    • Puy-de-Dôme
      • Thiers
        • Lachaux
- (1998)
J. Geffroy
  • Bourgogne-Franche-Comté
    • Saône-et-Loire
      • Charolles
        • Neuvy-Grandchamp
Marcel Roubault et al. (1960 -1965) +1 other reference
  • Nouvelle-Aquitaine
    • Deux-Sèvres
      • Bressuire
        • Mauléon
          • La Chapelle-Largeau
Lièvre et al. (2002)
        • Saint-Amand-sur-Sèvre
Lièvre et al. (2002)
    • Haute-Vienne
      • Bellac
        • Compreignac
- (1998)
- (1998)
      • Limoges
        • Saint-Sylvestre
- (1998)
  • Occitanie
    • Hérault
      • Lodève
        • Le Puech
Bariand et al. (1993) +1 other reference
        • Lodève
Henriot et al. (1998)
- (1998)
Germany
 
  • Baden-Württemberg
    • Freiburg Region
      • Ortenaukreis
        • Oberwolfach
Kolitsch (1997) +3 other references
      • Waldshut
        • St Blasien
          • Menzenschwand
Walenta (1989)
  • Bavaria
    • Upper Palatinate
      • Schwandorf District
        • Schwarzach bei Nabburg
          • Wölsendorf
      • Tirschenreuth District
        • Mähring
          • Poppenreuth bei Tirschenreuth
            • Uranium deposit
Weiß (1990)
Dill et al. (2010)
Greece
 
  • Attica
    • East Attica
      • Lavreotiki
        • Plaka
          • Paliokamariza Mines (Paleokamariza Mines)
Rieck et al. (2018)
India
 
  • Andhra Pradesh
    • Nellore District
Singh et al. (2015)
    • Srikakulam District
SINGH et al. (2014)
Italy
 
  • Sardinia
    • Metropolitan City of Cagliari
      • Capoterra
Olmi F.
  • Trentino-Alto Adige (Trentino-South Tyrol)
    • Trento Province
      • Borgo Chiese
        • Condino
Campostrini et al. (2006)
Mexico
 
  • Chihuahua
    • Aldama Municipality
      • Peña Blanca District
        • Sierra Peña Blanca
www.swri.org (2001)
Slovakia
 
  • Banská Bystrica Region
    • Rimavská Sobota District
Koděra (1986)
  • Košice Region
    • Spišská Nová Ves District
      • Hnilčík
Koděra (1986)
      • Spišská Nová Ves
        • Novoveská Huta
Koděra (1986)
USA
 
  • Colorado
    • Gunnison County
Eckel et al. (1997)
    • Saguache County
Gross (1965) +1 other reference
Eckel et al. (1997)
 
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