Silicocarnotite, Ca5m[(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

Evgeny V. Galuskin, Irina O. Galuskina, Frank Gfeller, Biljana Krüger, Joachim Kusz, Yevgeny Vapnik, Mateusz Dulski, Piotr Dzierzanowski

Research output: Contribution to journalArticlepeer-review

32 Scopus citations

Abstract

The new mineral silicocarnotite, Ca5[(SiO4)(PO4)](PO)4 (Pnma; a = 6.72230(1), b = 15.4481(2), c = 10.0847(2) A; V = 1047.37(2) A, Z = 4), has been discovered in pyrometamorphic gehlenite-bearing rocks of the Hatrurim Complex, Negev Desert, Israel. The name "silicocarnotite" has been used for the synthetic phase Ca5[(SiO4)(PO4)](PO)4 for more than 100 years. The holotype specimen is a gehlenite-fluorapatite rock with minor andradite and pseudowollastonite. Silicocarnotite is colourless with a white streak and a vitreous lustre. The microhardness is VHN50 = 523-552 kg m-2, mean = 537 kg m-2. Mohs hardness is about 5. Cleavage and parting are not observed. The calculated density is 3.06 g cm-3. Silicocarnotite is biaxial (+), with a = 1.618(2), β = 1.621(2), γ = 1.628(2) (589 nm), 2V (meas.) = 75(5)o, 2VZ (calc.) = 67o; dispersion is medium, r > v; the orientation is X|| b, Y|| a, Z || c; the mineral is nonpleochroic. The empirical formula of holotype silicocarnotite is Ca5011Sr0.006P1.774 Si1.106S6+0.113O12. The strongest diffraction lines are [dhkl, (I)]: 2.815(100), 2.596(62), 2.575(50), 3.285(48), 3.903(40), 3.007(39), 3.176(36), 1.746(29), 3.082 (29). Minerals of the silicocarnotite-ternesite solid solution, Ca5[(SiO)4(PO4)](PO)4-Ca5(SiO4)2SO4, occur in larnite- and gehlenitebearing pyrometamorphic rocks of the Hatrurim Complex, distributed in the Dead Sea rift area on the territories of Israel, Palestine and Jordan. New data on morphology, composition, structure, mineral associations, mechanisms and conditions of growth of the ternesite-silicocarnotite solid-solution series are presented. Large ternesite porphyroblasts (metacrysts) in fine-grained larnite-ye'elimite matrix are the most striking evidence for high-temperature alterations of early "clinker minerals". Silicocarnotite-ternesite grains grew as a result of reactions between primary pyrometamorphic minerals (larnite, flamite, fluorellestadite-fluorapatite) with sulphate-bearing melts, which are side-products of the combustion processes during the pyrometamorphism.

Original languageEnglish
Pages (from-to)105-123
Number of pages19
JournalEuropean Journal of Mineralogy
Volume28
Issue number1
DOIs
StatePublished - 1 Apr 2016

Keywords

  • Calcium silicophosphate
  • Combustion processes
  • Crystal structure
  • Hatrurim Complex
  • Metacrysts
  • New mineral
  • P-bearing ternesite
  • Pyrometamorphism
  • Raman
  • Silicocarnotite
  • Solid solution

ASJC Scopus subject areas

  • Geochemistry and Petrology

Fingerprint

Dive into the research topics of 'Silicocarnotite, Ca5m[(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'. Together they form a unique fingerprint.

Cite this