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Silicocarnotite

A valid IMA mineral species
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05227380017271921973150.jpg
Marie-Adolphe Carnot
Formula:
Ca5[(SiO4)(PO4)](PO4)
May also be written Ca5SiP2O12 or Ca5(PO4)2SiO4.
Colour:
Colourless (natural); blue (synthetic)
Lustre:
Vitreous
Hardness:
5
Specific Gravity:
3.063 (Calculated)
Crystal System:
Orthorhombic
Name:
Synthetic material was discovered in slag by Adolphe Carnot and A. Richard in 1883. The material was named by Kroll in 1911 after Carnot. The name silicocarnotite has been used for the synthetic phase Ca5[(SiO4)(PO4)](PO)4 since then. The natural mineral was described by Galuskin et al. in 2016 and they kept the same name.

Marie Adolphe Carnot (27 January 1839, Paris, France – 20 June 1920) was a French chemist, mining engineer and politician. He was a chemistry professor at École des Mines in Paris and later Chief Engineer of Mines and Inspector General of Mines, becoming Dean of the École Nationale des Mines in 1901-1907, when he retired. The unrelated mineral carnotite is also named after him.
Dimorph of:
Tsangpoite
Isotypic with ternesite. A member of the ternesite-silicocarnotite solid solution. Chemically similar to nagelschmidtite and 'ciplyite'.

Known for a long time as an artificial, calcium silico-phosphate in slag.

Natural material was found within the Hatrurim Complex. It is result of pyrometamorphism, and more specifically an interaction of primary "clinker minerals" (flamite, fluorellestadite-fluorapatite, larnite) with sulphate-bearing melts.



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Unique IdentifiersHide

Mindat ID:
9647
Long-form identifier:
mindat:1:1:9647:4

IMA Classification of SilicocarnotiteHide

Classification of SilicocarnotiteHide

Strunz-mindat (2026):
9.AH.20

9 : SILICATES (Germanates)
A : Nesosilicates
H : Nesosilicates with CO3, SO4, PO4, etc.

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

Physical Properties of SilicocarnotiteHide

Lustre:
Vitreous
Transparency:
Transparent
Colour:
Colourless (natural); blue (synthetic)
Streak:
White
Hardness:
5 on Mohs scale
Hardness:
VHN50=537 kg/mm2 - Vickers
Comment:
ca. 5
Tenacity:
Brittle
Cleavage:
None Observed
Parting:
Not observed
Fracture:
Irregular/Uneven
Density:
3.063(1) g/cm3 (Calculated)

Optical Data of SilicocarnotiteHide

Type:
Biaxial (+)
RI values:
nα = 1.618(2) nβ = 1.621(2) nγ = 1.628(2)
2V:
Measured: 75° (5), Calculated: 67°
Max. Birefringence:
δ = 0.010
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. Each grain retains its interference colour (retardation) while its brightness falls to black at extinction and reaches a maximum between extinction positions.

Surface Relief:
High (positive)
Relative to Canada balsam mounting medium (n ≈ 1.537).

This shows the grain boundary and Becke line effect under plane-polarised light, based on the contrast between this mineral's average refractive index and the mounting medium. It does not take into account mineral colouration.
In focus
Interference Figure:
This shows the idealized biaxial acute bisectrix (Bxa) interference figure - the conoscopic view for a grain cut perpendicular to the acute bisectrix, using this mineral's 2V. The two small white dots mark the melatopes - the points where the two optic axes emerge - and are shown only when they fall within the field of view. The coloured bands are isochromatics, and the dark bands are isogyres.

Rotate the stage: at 0°/90° the isogyres form a cross through the melatopes; at 45° they pull apart into curved hyperbolas. That splitting on rotation - absent in a uniaxial figure - is the standard diagnostic test for telling biaxial minerals from uniaxial ones. If 2V is large, the melatopes may fall outside the field of view, as they often do at the microscope too.
Dispersion:
medium (r > v)
Pleochroism:
Non-pleochroic

Chemistry of SilicocarnotiteHide

Mindat Formula:
Ca5[(SiO4)(PO4)](PO4)

May also be written Ca5SiP2O12 or Ca5(PO4)2SiO4.
Element Weights:
Element% weight
Ca41.539 %
O39.798 %
P12.841 %
Si5.822 %

Calculated from ideal end-member formula.
Ca
O
P
Si
Elements listed:
Ca, O, P, Si - search for minerals with similar chemistry
Common Impurities:
S

Crystallography of SilicocarnotiteHide

Crystal System:
Orthorhombic
Class (H-M):
mmm(2/m2/m2/m) - Dipyramidal
Space Group:
Pnma
Setting:
Pnma
Cell Parameters:
a = 6.7230(1) Å, b = 15.4481(2) Å, c = 10.0847(2) Å
Ratio:
a:b:c = 0.435 : 1 : 0.653
Unit Cell V:
1047.37 ų
Z:
4

X-Ray Powder DiffractionHide

Powder Diffraction Data:
d-spacingIntensity
2.815 Å(100)
2.596 Å(62)
2.575 Å(50)
3.285 Å(48)
3.903 Å(40)
3.007 Å(39)
3.176 Å(36)
1.746 Å(29)
3.082 Å(29)
Comments:
Concerns the natural material.

Geological EnvironmentHide

Paragenetic Mode(s):
Paragenetic ModeEarliest Age (Ga)
Stage 10a: Neoproterozoic oxygenation/terrestrial biosphere<0.6
51 : Pyrometamorphic minerals (see also #54 and #56)<0.36

Type Occurrence of SilicocarnotiteHide

Synonyms of SilicocarnotiteHide

Other Language Names for SilicocarnotiteHide

Relationship of Silicocarnotite to other SpeciesHide

Related Minerals - Strunz-mindat GroupingHide

9.AH.Fluorbritholite-(Nd)Ca2Nd3(SiO4)3FHex. 6/m : P63/m
9.AH.05Iimoriite-(Y)Y2[SiO4][CO3]Tric. 1 : P1
9.AH.10Tundrite-(Ce)Na2Ce2Ti(SiO4)(CO3)2O2Tric. 1 : P1
9.AH.10Tundrite-(Nd)Na2(Nd,Ce)2Ti(SiO4)(CO3)2O2
9.AH.15GaluskiniteCa7(SiO4)3(CO3) Mon. 2/m : P21/b
9.AH.15SpurriteCa5(SiO4)2(CO3)Mon. 2/m : P21/b
9.AH.20TernesiteCa5(SiO4)2(SO4)Orth. mmm(2/m2/m2/m) : Pnma
9.AH.25Britholite-(Ce)(Ce,Ca)5(SiO4)3OHHex. 6/m : P63/m
9.AH.25Britholite-(Y)(Y,Ca)5(SiO4)3OHHex. 6/m : P63/m
9.AH.25MattheddleitePb5(SiO4)1.5(SO4)1.5(Cl,OH)Hex. 6/m : P63/m
9.AH.25Fluorbritholite-(Ce)(Ce,Ca)5(SiO4)3FHex. 6/m : P63/m
9.AH.25FluorellestaditeCa5(SiO4)1.5(SO4)1.5FHex. 6/m : P63/m
9.AH.25Fluorbritholite-(La)Ca2La3(SiO4)3FHex. 6/m : P63/m
9.AH.25Fluorbritholite-(Y)(Y,Ca)5(SiO4)3FHex. 6/m : P63/m
9.AH.25HydroxylellestaditeCa5(SiO4)1.5(SO4)1.5(OH)Hex. 6/mmm(6/m2/m2/m) : P63/mcm
9.AH.25'Calciobritholite'(Ca,Y)5(SiO4,PO4)3(OH)
9.AH.25'Britholite-(La)'Ca2(La,Ce,Ca)3(SiO4,PO4)3(OH,F)
9.AH.25Tritomite-(Ce)Ce5(SiO4,BO4)3(OH,O)
9.AH.25Tritomite-(Y)Y5(SiO4,BO4)3(O,OH,F)
9.AH.25Fluorcalciobritholite(Ca,REE)5(SiO4,PO4)3FHex. 6/m : P63/m
9.AH.25ChlorellestaditeCa5(SiO4)1.5(SO4)1.5ClHex. 6/m : P63/m
9.AH.35DargaiteBaCa12(SiO4)4(SO4)2O3Trig. 3m(32/m) : R3m
9.AH.35NabimusaiteKCa12(SiO4)4(SO4)2O2FTrig. 3m(32/m) : R3m
9.AH.40StracheriteBaCa6(SiO4)2[(PO4)(CO3)]FTrig. 3m(32/m) : R3m
9.AH.40ZadoviteBaCa6[(SiO4)(PO4)](PO4)2FTrig. 3m : R3m
9.AH.40GazeeviteBaCa6(SiO4)2(SO4)2OTrig. 3m(32/m) : R3m
9.AH.45FlamiteCa8-x(Na,K)x(SiO4)4-x(PO4)xOrth. mm2
9.AH.50ByzantieviteBa5(Ca,REE,Y)22(Ti,Nb)18(SiO4)4[(PO4),(SiO4)]4(BO3)9O22[(OH),F]43(H2O)1.5Trig. 3 : R3
9.AH.55Greenwoodite(Ba,V3+O)2V3+9(Fe3+,Fe2+)2Si2O22Trig. 3m(32/m) : P3m1
9.AH.60Kihlmanite-(Ce)Ce2TiO2(SiO4)(HCO3)2(H2O)Tric. 1 : P1
9.AH.65TsangpoiteCa5(PO4)2(SiO4)Hex.
9.AH.70'Enalite'(Th,REE,Al) [(PO4),(SiO4),(OH)]Tet.

Fluorescence of SilicocarnotiteHide

Other InformationHide

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 SilicocarnotiteHide

References for SilicocarnotiteHide

Reference List:
Carnot, A., Richard, A. (1883) Silicophosphate de chaux cristallisé produit dans la déphosphoration des fontes. Comptes Rendus Hebdomadaires des Séances de l'Académie des Sciences, Paris: 97: 316–320.
Kroll, V.A. (1911) Researches on the nature of the phosphates contained in basic slags derived from the Thomas-Gilchrist dephosphorisation process. The Journal of the Iron and Steel Institute: 84: 126–187.
Riley, D.P., Phil, D., Segnit, E.R. (1948) An optical and X-ray examination of the basic-slag mineral silicocarnotite. Mineralogical Magazine: 28: 496-504.
Dickens, B., Brown, W. E. (1971) The crystal structure of Ca5(PO4)2SiO4 (Silico-Carnotite). TMPM Tschermaks Mineralogische und Petrographische Mitteilungen, 16 (1). 1-27 doi:10.1007/bf01099075
Galuskin, E. et al. (2014): Silicocarnotite, an old and potentially new mineral from the Negev Desert, Israel. 21st General Meeting of the IMA (IMA2014), Gauteng, South Africa, September 1-5; Abstract Volume, 377.
Galuskin, Evgeny V., Galuskina, Irina O., Gfeller, Frank, Krüger, Biljana, Kusz, Joachim, Vapnik, Yevgeny, Dulski, Mateusz, Dzierżanowski, Piotr (2016) Silicocarnotite, Ca5[(SiO4)(PO4)](PO4), a new ,,old'' mineral from the Negev Desert, Israel, and the ternesite–silicocarnotite solid solution: indicators of high-temperature alteration of pyrometamorphic rocks of the Hatrurim Complex, Southern Levant. European Journal of Mineralogy, 28 (1) 105-123 doi:10.1127/ejm/2015/0027-2494
(2017) Silicocarnotite. Handbook of Mineralogy. Mineralogical Society of America
Galuskin, Evgeny V., Galuskina, Irina O., Książek, Maria, Kusz, Joachim, Vapnik, Yevgeny, Zieliński, Grzegorz (2024) The Crystal Chemistry and Structure of V-Bearing Silicocarnotite from Andradite–Gehlenite–Pseudowollastonite Paralava of the Hatrurim Complex, Israel. Minerals, 14 (12). doi:10.3390/min14121301

Localities for SilicocarnotiteHide

Showing 5 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.
China
 
  • Sichuan
    • Panzhihua
      • Miyi County
        • Haita town
          • Uranium deposits
Zhao et al. (2026)
Israel (TL)
 
  • Southern District
    • Beersheba Subdistrict
      • Tamar Regional Council
        • Hatrurim Basin
Galuskin et al. (2016)
          • Wadi Zohar
Galuskin et al. (2024)
Galuskin et al. (2016)
Palestine
 
  • West Bank
    • Quds Governorate
Galuskin et al. (2016)
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