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Magnioursilite

A valid IMA mineral species - grandfathered
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About MagnioursiliteHide

Formula:
Mg4(UO2)4(Si2O5)5(OH)6 · 20H2O
Colour:
Lemon-yellow
Hardness:
3
Specific Gravity:
3.254
Name:
Named for its chemical composition as a magnesium uranyl silicate.
Magnioursilite was originally described in 1957 as “ursilite” (now discredited) from the Oktyabr’skoye deposit, Kyzyltyube-Saj, Samgar Steppe, Tajikistan.

Forms a solid solution with calcioursilite.


Unique IdentifiersHide

Mindat ID:
11332
Long-form identifier:
mindat:1:1:11332:8

IMA Classification of MagnioursiliteHide

Approved, 'Grandfathered' (first described prior to 1959)
IMA Formula:
Mg4(U6+O2)4(Si2O5)5(OH)6·20H2O
First published:
1957

Classification of MagnioursiliteHide

9.AK.35

9 : SILICATES (Germanates)
A : Nesosilicates
K : Uranyl neso- and polysilicates

Mineral SymbolsHide

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

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

Physical Properties of MagnioursiliteHide

Colour:
Lemon-yellow
Hardness:
Tenacity:
Brittle
Density:
3.254 g/cm3 (Measured)    

Chemistry of MagnioursiliteHide

Mindat Formula:
Mg4(UO2)4(Si2O5)5(OH)6 · 20H2O
Element Weights:
Element% weight
U41.030 %
O40.679 %
Si12.103 %
Mg4.190 %
H1.998 %

Calculated from ideal end-member formula.
U
O
Si
Mg
H

X-Ray Powder DiffractionHide

Powder Diffraction Data:
d-spacingIntensity
4.98 Å(100)
4.58 Å(80)
3.37 Å(80)
3.06 Å(100)
2.42 Å(60)
2.30 Å(90)
2.20 Å(50)
2.07 Å(90)
1.981 Å(60)
1.798 Å(60)
Comments:
Oktyabr'skoye U Deposit, Tajikistan. The data are from the Chernikov et al. (1957).

Geological EnvironmentHide

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

Type Occurrence of MagnioursiliteHide

General Appearance of Type Material:
Lemon-yellow earthy or nodular incrustations, rarely radiating spherulites.
Place of Conservation of Type Material:
No defined type material.
Geological Setting of Type Material:
Occurs along joints in granite porphyry.
Associated Minerals at Type Locality:

Synonyms of MagnioursiliteHide

Ursilite (in part)

Other Language Names for MagnioursiliteHide

Common AssociatesHide

Associations Based on Photo Data:
2 photos of Magnioursilite associated with Blatonite(UO2)CO3 · H2O

Related Minerals - Strunz-mindat GroupingHide

9.AK.'Orlite'Pb3(UO2)3(Si2O7)2 · 6H2O
9.AK.05Soddyite(UO2)2SiO4 · 2H2OOrth. mmm(2/m2/m2/m) : Fddd
9.AK.10SklodowskiteMg(UO2)2(SiO3OH)2 · 6H2OMon. 2/m : B2/m
9.AK.10CuprosklodowskiteCu(UO2)2(SiO3OH)2 · 6H2OTric. 1 : P1
9.AK.10OursiniteCo(UO2)2(SiO3OH)2 · 6H2OOrth. mmm(2/m2/m2/m) : Cmca
9.AK.15ParauranophaneCa(UO2)2(SiO3OH)2 · 5H2OMon. 2/m : P21/b
9.AK.15UranophaneCa(UO2)2(SiO3OH)2 · 5H2OMon. 2 : P21
9.AK.15NatroboltwooditeNa(UO2)(SiO3OH) · H2OOrth. 222 : P212121
9.AK.15KasolitePb(UO2)(SiO4) · H2OMon. 2/m : P21/b
9.AK.15Boltwoodite(K,Na)(UO2)(SiO3OH) · 1.5H2OMon. 2 : P21
9.AK.20Swamboite-(Nd)Nd0.333[(UO2)(SiO3OH)](H2O)~2.5Mon. 2/m : P21/b
9.AK.25HaiweeiteCa(UO2)2[Si5O12(OH)2] · 6H2OOrth. mmm(2/m2/m2/m) : Pbcn
9.AK.25MetahaiweeiteCa(UO2)2Si6O15 · nH2OMon. 2/m : P2/b
9.AK.30WeeksiteK2(UO2)2(Si5O13) · 4H2OMon. 2/m : B2/m
9.AK.30CoutinhoiteThxBa(1-2x)(UO2)2Si5O13 · (H2O)1+y (0 < x < 0.5 and 0 < y < (2+x))Orth. mmm(2/m2/m2/m)
9.AK.30Barronite(◻0.5Ba0.5)(UO2)2Si5O12(OH) · 2H2OMon. 2/m : B2/m
9.AK.35CalcioursiliteCa4(UO2)4(Si2O5)5(OH)6 · 15H2OOrth.
9.AK.40UranosiliteUO3 · 7SiO2Orth.

RadioactivityHide

Radioactivity:
Element % Content Activity (Bq/kg) Radiation Type
Uranium (U) 41.0303% 10,257,575 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

Fluorescence of MagnioursiliteHide

Fluorescent in greenish yellow under ultraviolet light.

Other InformationHide

Notes:
Easily soluble in acids (especially when warm), turning the solution green and yielding silica gel.
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 MagnioursiliteHide

References for MagnioursiliteHide

Localities for MagnioursiliteHide

Showing 2 localities.

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.
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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.
Germany
 
  • Saxony
    • Erzgebirgskreis
      • Annaberg-Buchholz
        • Kleinrückerswalde
In the collection of Chuck Adan. ... +1 other reference
Tajikistan (TL)
 
  • Sughd
    • Khodzhent (Leninabad)
      • Kyzyltyube-Sai
Chernikov et al. (1977) +1 other reference
 
and/or  
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