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Steudelite

A valid IMA mineral species
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02109750017851543988069.jpg
Steudelite

Biachella Valley, Sacrofano, Metropolitan City of Rome Capital, Lazio, Italy
02109750017851543988069.jpg
Steudelite

Biachella Valley, Sacrofano, Metropolitan City of Rome Capital, Lazio, Italy
08215000017866506219928.jpg
Steudelite

Biachella Valley, Sacrofano, Metropolitan City of Rome Capital, Lazio, Italy
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About SteudeliteHide

01001630017272473388008.jpg
Prof Ralf Steudel / Chemist, Institute of Technology Berlin (Germany)
Formula:
Na3(K17Ca7)Ca4(Al24Si24O96)(SO3)6F6 · 4H2O
also given as (Na3☐)[(K,Na)17Ca7]Ca4(Al24Si24O96)(SO3)6F6·4H2O
Colour:
colourless
Hardness:
5
Specific Gravity:
2.51
Crystal System:
Hexagonal
Name:
Named in honour of Prof. Ralf Steudel (25 March 1937 – 12 February 2021) - an outstanding German chemist, specializing in the chemistry of sulphur.
The first sulfite-fluoride mineral (not to be mistaken for the fluorosulfate anion in reederite-(Y)) to date. Chemically somewhat similar to sacrofanite and delhayelite.

Crystal structure details:
* afghanite-type aluminosilicate framework
* within it, a column of cancrinite cages
* also isolated cancrinite and liottite cages occur there
* sulfite(IV) and lesser sulfate(VI) anions reside within the liottite cage


Unique IdentifiersHide

Mindat ID:
55454
Long-form identifier:
mindat:1:1:55454:3

IMA Classification of SteudeliteHide

IMA status:
Approved
IMA Formula:
Na3◻(K17Ca7)Ca4(Al24Si24O96)(S4+O3)6F6·4H2O
Approval year:
2021

Classification of SteudeliteHide

Strunz-mindat (2026):
9.FB.

9 : SILICATES (Germanates)
F : Tektosilicates without zeolitic H2O
B : Tektosilicates with additional anions

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

Physical Properties of SteudeliteHide

Colour:
Colourless
Hardness:
5 on Mohs scale
Tenacity:
Brittle
Cleavage:
Distinct/Good
on {1010}
Parting:
perfect, on {0001}
Fracture:
Irregular/Uneven
Density:
2.51(1) g/cm3 (Measured)    2.511 g/cm3 (Calculated)

Chemistry of SteudeliteHide

Mindat Formula:
Na3(K17Ca7)Ca4(Al24Si24O96)(SO3)6F6 · 4H2O

also given as (Na3☐)[(K,Na)17Ca7]Ca4(Al24Si24O96)(SO3)6F6·4H2O
Element Weights:
Element% weight
O40.182 %
Si14.346 %
K14.147 %
Al13.782 %
Ca9.383 %
S4.095 %
F2.426 %
Na1.468 %
H0.172 %

Calculated from ideal end-member formula.
O
Si
K
Al
Ca
S
F
Na
H
Elements listed:
Al, Ca, F, H, K, Na, O, S, Si - search for minerals with similar chemistry

Crystallography of SteudeliteHide

Crystal System:
Hexagonal
Class (H-M):
6m2 - Ditrigonal Dipyramidal
Space Group:
P62c
Cell Parameters:
a = 12.8953(1) Å, c = 21.2778(3) Å
Ratio:
a:c = 1 : 1.65
Unit Cell V:
3,064.22 ų (Calculated from Unit Cell)

X-Ray Powder DiffractionHide

Powder Diffraction Data:
d-spacingIntensity
11.15 Å(28)
4.799 Å(25)
3.973 Å(16)
3.721 Å(47)
3.305 Å(100)
2.661 Å(17)
2.471 Å(14)
2.149 Å(21)
Locality:
Biachella Valley, Sacrofano, Metropolitan City of Rome Capital, Lazio, Italy

Type Occurrence of SteudeliteHide

Type Locality:
ⓘ Biachella Valley, Sacrofano, Metropolitan City of Rome Capital, Lazio, Italy
General Appearance of Type Material:
thick-tabular, isometric and short-prismatic crystals, up to 7 mm in size
Place of Conservation of Type Material:
collections of the Fersman Mineralogical Museum, Russian Academy of Sciences, Leninskiy Prospekt 18-2, Moscow 119071, Russia, registration number 5665/1
Geological Setting of Type Material:
syenite ejectum
Associated Minerals at Type Locality:
AndraditeBiachellaiteBiotiteDiopsideHaüyne
LeuciteLiottiteSacrofaniteSanidineSmectite Group

Synonyms of SteudeliteHide

Other Language Names for SteudeliteHide

German:Steudelit

Relationship of Steudelite to other SpeciesHide

Member of:
Cancrinite Group > Feldspathoid Group
Other Members of Cancrinite Group:
Afghanite(Na,K)22Ca10(Si24Al24O96)(SO4)6Cl6Trig. 3m : P31c
Alloriite(Na,Ca,K)26Ca4(Al6Si6O24)4(SO4)6Cl6Trig. 3m : P31c
Balliranoite(Na,K)6Ca2(Si6Al6O24)Cl2(CO3)Hex. 6 : P63
BetziteNa6Ca2(Al6Si6O24)Cl4Hex. 6 : P63
Biachellaite(Na,Ca,K)8(Al6Si6O24)(SO4)2(OH)0.5 · H2OTrig. 3 : P3
Bystrite(Na,K)7Ca(Al6Si6O24)(S5)ClTrig. 3m : P31c
Cancrinite(Na,Ca,◻)8(Al6Si6O24)(CO3,SO4)2 · 2H2OHex. 6 : P63
CancrisiliteNa7(Al5Si7O24)(CO3) · 3H2OHex. 6mm : P63mc
CarbobystriteNa8(Al6Si6O24)(CO3) · 3.5H2OTrig. 3m : P31c
Davyne(Na,K)6Ca2(Al6Si6O24)(Cl2,SO4)2Hex. 6/m : P63/m
DepmeieriteNa8(Al6Si6O24)(PO4,CO3)1-x · 3H2O (x<0.5)Hex. 6 : P63
Fantappièite[Na82.5Ca33K16.5](Si99Al99O396)(SO4)33 · 4H2OTrig. 3 : R3
Farneseite(Na,Ca,K)56(Al6Si6O24)7(SO4)12 · 6H2OHex. 6/m : P63/m
Franzinite(Na,K)6Ca2(Al6Si6O24)(SO4)2 · 0.5H2OHex.
Giuseppettite(Na,K,Ca)7-8(Al6Si6O24)(SO4,Cl)1-2Trig. 3m : P31c
HydroxycancriniteNa8(Al6Si6O24)(OH)2 · 2H2OHex. 6 : P63
KircheriteNa5Ca2K(Al6Si6O24)(SO4)2 · 0.33H2OTrig. 32 : R32
KyanoxaliteNa7(Al6-xSi6+xO24)(C2O4)0.5+x · 5H2O (0 < x < 0.5)Hex. 6 : P63
Liottite(Na,K)16Ca8(Al6Si6O24)3(SO4)5Cl4Hex. 6 : P6
Marinellite(Na,K)42Ca6(Al6Si6O24)6(SO4)8Cl2 · 3H2OTrig. 3m : P31c
MicrosommiteNa4K2Ca2(Al6Si6O24)(SO4)Cl2Hex. 622 : P6322
PitiglianoiteNa6K2(Al6Si6O24)(SO4) · 2H2OHex. 6 : P63
Quadridavyne(Na,K)6Ca2(Al6Si6O24)Cl4Hex. 6/m : P63/m
Sacrofanite(Na61K19Ca32)(Si84Al84O336)(SO4)26Cl2F6 · 2H2OHex.
SulfhydrylbystriteNa5K2Ca[Al6Si6O24](S5)2(SH)Trig. 3m : P31c
Tounkite(Na,Ca,K)8(Si6Al6)O24(SO4)2Cl · 0.5H2OHex. 622 : P6222
'UM2004-48-SiO:AlClCaNaS'(Na,Ca)8(Si6Al6)O24(SO4)1.7Cl1.3
'UM2009-23-SiO:AlCCaClHKNaS'(Na,Ca)24K10[(Si,Al)60O120](SO4)5.6Cl1.5(CO3)0.4 · 11H2OTrig. 3 : P3
Vishnevite(Na,K)8(Al6Si6O24)(SO4,CO3) · 2H2OHex. 6 : P63

Related Minerals - Strunz-mindat GroupingHide

9.FB.Perchukite-(Y)PbYAsSi2O8Mon. 2/m : B2/b
9.FB.Åsgruvanite-(Ce)Ce16Ca5Al(SiO4)6(AsO3)8(CO3)2Cl4F3(OH)2Trig. 3m(32/m) : P3m1
9.FB.Wenlanzhangite-(Y)Y2V3+2V4+2(SiO4)2O4(OH)4Tric. 1 : P1
9.FB.SlyudyankaiteNa28Ca4(Si24Al24O96)(SO4)6(S6)1/3(CO2) · 2H2OTric. 1 : P1
9.FB.Bolotinaite(Na7◻)(Al6Si6O24)F · 4H2OIso. 43m : I43m
9.FB.SapozhnikoviteNa8(Al6Si6O24)(HS)2Iso. 43m : P43n
9.FB.BetziteNa6Ca2(Al6Si6O24)Cl4Hex. 6 : P63
9.FB.05Quadridavyne(Na,K)6Ca2(Al6Si6O24)Cl4Hex. 6/m : P63/m
9.FB.05SulfhydrylbystriteNa5K2Ca[Al6Si6O24](S5)2(SH)Trig. 3m : P31c
9.FB.05Marinellite(Na,K)42Ca6(Al6Si6O24)6(SO4)8Cl2 · 3H2OTrig. 3m : P31c
9.FB.05Afghanite(Na,K)22Ca10(Si24Al24O96)(SO4)6Cl6Trig. 3m : P31c
9.FB.05Bystrite(Na,K)7Ca(Al6Si6O24)(S5)ClTrig. 3m : P31c
9.FB.05Franzinite(Na,K)6Ca2(Al6Si6O24)(SO4)2 · 0.5H2OHex.
9.FB.05KyanoxaliteNa7(Al6-xSi6+xO24)(C2O4)0.5+x · 5H2O (0 < x < 0.5)Hex. 6 : P63
9.FB.05Vishnevite(Na,K)8(Al6Si6O24)(SO4,CO3) · 2H2OHex. 6 : P63
9.FB.05Farneseite(Na,Ca,K)56(Al6Si6O24)7(SO4)12 · 6H2OHex. 6/m : P63/m
9.FB.05Alloriite(Na,Ca,K)26Ca4(Al6Si6O24)4(SO4)6Cl6Trig. 3m : P31c
9.FB.05Liottite(Na,K)16Ca8(Al6Si6O24)3(SO4)5Cl4Hex. 6 : P6
9.FB.05DepmeieriteNa8(Al6Si6O24)(PO4,CO3)1-x · 3H2O (x<0.5)Hex. 6 : P63
9.FB.05Biachellaite(Na,Ca,K)8(Al6Si6O24)(SO4)2(OH)0.5 · H2OTrig. 3 : P3
9.FB.05Cancrinite(Na,Ca,◻)8(Al6Si6O24)(CO3,SO4)2 · 2H2OHex. 6 : P63
9.FB.05CancrisiliteNa7(Al5Si7O24)(CO3) · 3H2OHex. 6mm : P63mc
9.FB.05Fantappièite[Na82.5Ca33K16.5](Si99Al99O396)(SO4)33 · 4H2OTrig. 3 : R3
9.FB.05CarbobystriteNa8(Al6Si6O24)(CO3) · 3.5H2OTrig. 3m : P31c
9.FB.05MicrosommiteNa4K2Ca2(Al6Si6O24)(SO4)Cl2Hex. 622 : P6322
9.FB.05PitiglianoiteNa6K2(Al6Si6O24)(SO4) · 2H2OHex. 6 : P63
9.FB.05Tounkite(Na,Ca,K)8(Si6Al6)O24(SO4)2Cl · 0.5H2OHex. 622 : P6222
9.FB.05Balliranoite(Na,K)6Ca2(Si6Al6O24)Cl2(CO3)Hex. 6 : P63
9.FB.05Giuseppettite(Na,K,Ca)7-8(Al6Si6O24)(SO4,Cl)1-2Trig. 3m : P31c
9.FB.05Sacrofanite(Na61K19Ca32)(Si84Al84O336)(SO4)26Cl2F6 · 2H2OHex.
9.FB.05KircheriteNa5Ca2K(Al6Si6O24)(SO4)2 · 0.33H2OTrig. 32 : R32
9.FB.05HydroxycancriniteNa8(Al6Si6O24)(OH)2 · 2H2OHex. 6 : P63
9.FB.05Davyne(Na,K)6Ca2(Al6Si6O24)(Cl2,SO4)2Hex. 6/m : P63/m
9.FB.10HaüyneNa3Ca(Si3Al3)O12(SO4)Iso. 43m : P43n
9.FB.10LazuriteNa7Ca(Al6Si6O24)(SO4)(S3) · H2OIso. 43m : P43n
9.FB.10DanaliteBe3Fe2+4(SiO4)3SIso. 43m : P43n
9.FB.10HelvineBe3Mn2+4(SiO4)3SIso. 43m : P43n
9.FB.10KamaishiliteCa2(Al2SiO6)(OH)2Tet.
9.FB.10SodaliteNa4(Si3Al3)O12ClIso. 43m : P43n
9.FB.10NoseanNa8(Al6Si6O24)(SO4) · H2OIso. 43m : P43n
9.FB.10GenthelviteBe3Zn4(SiO4)3SIso. 43m : P43n
9.FB.10BicchuliteCa2(Al2SiO6)(OH)2Iso. 43m : I43m
9.FB.10Tsaregorodtsevite(N(CH3)4)(AlSi5O12)Orth. 222 : I222
9.FB.10VladimirivanoviteNa6Ca2(Al6Si6O24)(SO4,S3,S2,Cl)2 · H2OOrth. mmm(2/m2/m2/m)
9.FB.10Tugtupite(BeAlSi)Na4(SiO4)3ClTet. 4 : I4
9.FB.15MarialiteNa4Al3Si9O24ClTet. 4/m : I4/m
9.FB.15MeioniteCa4Al6Si6O24CO3Tet. 4/m : I4/m
9.FB.15Silvialite(Ca,Na)4(Al6Si6O24)(SO4,CO3)Tet. 4/m : I4/m

RadioactivityHide

Radioactivity:
Element % Content Activity (Bq/kg) Radiation Type
Uranium (U) 0.0000% 0 α, β, γ
Thorium (Th) 0.0000% 0 α, β, γ
Potassium (K) 14.1465% 4,385 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

IR Spectrum:
confirms H2O, SO32–, and minor SO42-
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 SteudeliteHide

References for SteudeliteHide

Localities for SteudeliteHide

Showing 1 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.
Italy (TL)
 
  • Lazio
    • Metropolitan City of Rome Capital
      • Sacrofano
Miyawaki et al. (2021) +2 other references
Quick NavTopAbout SteudeliteUnique IdentifiersIMA Classification Classification Mineral SymbolsPhysical Properties Chemistry Crystallography X-Ray Powder DiffractionType Occurrence SynonymsOther LanguagesRelationshipsStrunz-MindatRadioactivityOther InformationInternet Links References Localities Locality List
 
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