Cronstedtite R061026
Name: Cronstedtite
RRUFF ID: R061026
Ideal Chemistry: (Fe2+,Fe3+)3(Si,Fe3+)2O5(OH)4
Locality: Kisbanya, Hungary
Source: Michael Scott S101349 [view label]
Owner: RRUFF
Description: Black elongated prismatic crystals with triangular cross-sections, polytype 3T
Status: The identification of this mineral is confirmed by single-crystal X-ray diffraction and chemical analysis.
Mineral Groups: [ Clay (86) ] [ serpentine (12) ]
CHEMISTRY 
RRUFF ID: R061026.2
Sample Description: Microprobe Fragment
Measured Chemistry: (Fe2+2.13Fe3+0.87)Σ=3(Si1.13Fe3+0.87)Σ=2O5(OH)4 ; Fe2 and Fe3 splitted by stoichiometry (sum of cations = 5) and charge balance
Microprobe Data File: [ Download Excel File ]
RAMAN SPECTRUM 
RRUFF ID:
Sample Description: Unoriented sample
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BROAD SCAN WITH SPECTRAL ARTIFACTS
RRUFF ID: R061026
Wavelength:
Sample Description: Unoriented sample
Instrument settings: Thermo Almega XR 532nm @ 100% of 150mW
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Raman Data (RAW) View Graph
RRUFF File
POWDER DIFFRACTION 
RRUFF ID: R061026.9
Sample Description: Single crystal, powder profile is calculated
Cell Refinement Output: a: 3.177(2)Å    b: 3.177(2)Å    c: 21.29(1)Å
alpha: 90°    beta: 90°    gamma: 120°   Volume: 186.1(1)Å3    Crystal System: hexagonal
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Calculated diffraction file.

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Output file from the Bruker D8 Advance instrument. Includes device headers and XY data.

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DIF File
X-ray Data (XY - RAW) View Graph
RRUFF File
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REFERENCES for Cronstedtite

American Mineralogist Crystal Structure Database Record: [view record]

Anthony J W, Bideaux R A, Bladh K W, and Nichols M C (1990) Handbook of Mineralogy, Mineral Data Publishing, Tucson Arizona, USA, by permission of the Mineralogical Society of America. [view file]

Steinmann J (1821) Chemische Untersuchung des Cronstedtit's, eines neuen Fossils von Pribram in Böhmen, Journal für Chemie und Physik, 32, 69-100   [view file]

Wiewióra A (1990) Crystallochemical classifications of phyllosilicates based on the unified system of projection of chemical composition: III. The serpentine-kaolin group, Clay Minerals, 25, 93-98   [view file]

Hybler J (2006) Parallel intergrowths in cronstedtite-1T: determination of the degree of disorder, European Journal of Mineralogy, 18, 197-205

Hybler J, Sejkora J, Venclík V (2016) Polytypism of cronstedtite from Pohled, Czech Republic, European Journal of Mineralogy, 28, 765-775

Hybler J (2016) Crystal structure of cronstedtite-6T2, a non-MDO polytype, European Journal of Mineralogy, 28, 777-788

Hybler J, Števko M, Sejkora J (2017) Polytypism of cronstedtite from Nižná Slaná, Slovakia, European Journal of Mineralogy, 29, 91-99

Pignatelli I, Mugnaioli E, Marrocchi Y (2018) Cronstedtite polytypes in the Paris meteorite, European Journal of Mineralogy, 30, 349-354