Chemistry:Sudoite
| Sudoite | |
|---|---|
| General | |
| Category | Chlorite group |
| Formula (repeating unit) | Mg2Al3(Si3Al)O10)(OH)8 |
| Crystal system | Monoclinic |
| Identification | |
| Color | White to light green |
| Mohs scale hardness | 2.5–3.5 |
| |re|er}} | pearly, dull |
| Refractive index | nα = 1.581 à 1.583 nβ = 1.584 à 1.589 nγ = 1.591 à 1.601 |
| Birefringence | biaxial (-) ; δ = 0.010 to 0.018 2V = 64 to 70° (measured) 2V = 68 to 72° (calculated) |
| References | .[1][2] |
Sudoite is a mineral from the chlorite group. It was named after Toshio Sudo (1911-2000), professor of mineralogy at the University of Tokyo, in Japan , and a pioneer of clay science.[3] The mineral tosudite also wears his name. It was approved as a valid species by the International Mineralogical Association in 1966.
Caracteristics
Sudoite is a clay mineral with chemical formula defined as Mg2Al3(Si3Al)O10)(OH)8. it has a monoclinic crystal system. Its hardness on the Mohs scale is comprised between 2.5 and 3.5.
Classification
Following the Nickel–Strunz classification, it is contained in the "09.EC.55" group:
| Mineral | Formula | Symmetry group | Space group |
|---|---|---|---|
| Baileychlore | (Zn,Al)3[Fe2Al][Si3AlO10](OH)8 | 1 or 1 | C1 or C1 |
| Borocookeite | Li1+3xAl4-x(BSi3)O10(OH,F)8 (x ≤ 0,33) | 2/m | C2/m |
| Chamosite | (Fe,Mg,Fe)5Al(Si3Al)O10(OH,O)8 | 2/m | C2/m |
| Clinochlore | (Mg,Fe)5Al(Si3Al)O10(OH)8 | 2/m | C2/m |
| Cookeite | LiAl4(Si3Al)O10(OH)8 | 1, 2 or 2/m | C1, C2 or Cc |
| Donbassite | Al2[Al2,33][Si3AlO10](OH)8 | 2/m | C2/m |
| Franklinfurnaceite | Ca(Fe,Al)Mn4Zn2Si2O10(OH)8 | 2 | C2 |
| Glagolevite | NaMg6[Si3AlO10](OH,O)8·H2O | 1 | C1 |
| Gonyerite | Mn3[Mn3Fe][(Si,Fe)4O10](OH,O)8 | unknown | |
| Nimite | (Ni,Mg,Fe)5Al(Si3Al)O10(OH)8 | 2/m | C2/m |
| Odinite | (Fe,Mg,Al,Fe,Ti,Mn)2,5(Si,Al)2O5(OH)4 | m | Cm |
| Orthochamosite | (Fe,Mg,Fe)5Al(Si3Al)O10(OH,O)8 | unknown | |
| Pennantite | Mn5Al(Si3Al)O10(OH)8 | 2/m | C2/m |
| Sudoite | Mg2(Al,Fe)3Si3AlO10(OH)8 | 2/m | C2/m |
Formation
It has been first discovered in the Knollenberg Keuper formation, in the village of Plochingen, Stuttgart Region (Baden-Württemberg, Germany ).[4] Despite being an unlikely mineral, it has been described in every continent but Antarctica and Oceania. It is found mainly in hydrothermal or high-pressure/low-temperature (HP/LT) metamorphism contexts[5][6][7]
Use
This mineral has been used as gemstone for the production of personal ornaments, beads and pendants, during the Early Ceramic Age (500 BC – 500 AD), in the Lesser Antilles.[8] The precise source of such formation of sudoite allowing to carve artifacts in rather large blocks remain unknown.
References
- ↑ Sudoite mineral information and data Mindat
- ↑ Sudoite Mineral Data Webmineral
- ↑ Kohyama, Norihiko (2000). "In memory of Prof. Toshio Sudo". Clay Science 11 (2): 103–105. doi:10.11362/jcssjclayscience1960.11.103.
- ↑ v. Engelhardt, W.; Müller, Germ; Kromer, H. (1962). "Dioktaedrischer Chlorit ("Sudoit") in Sedimenten des Mittleren Keupers von Plochingen (Württ.)". Naturwissenschaften 49 (9): 205–206. doi:10.1007/BF00633957. ISSN 1432-1904. Bibcode: 1962NW.....49..205V.
- ↑ Fransolet, André-Mathieu; Bourguignon, P. (1978). "Di/trioctahedral chlorite in quartz veins from the Ardenne, Belgium". The Canadian Mineralogist 16 (3): 365–373.
- ↑ Goffé, Bruno; Michard, André; Kienast, Jean Robert; Le Mer, Olivier (1988). "A case of obduction-related high-pressure, low-temperature metamorphism in upper crustal nappes, Arabian continental margin, Oman: P-T paths and kinematic interpretation". Tectonophysics. The Ophiolites of Man 151 (1): 363–386. doi:10.1016/0040-1951(88)90253-3. ISSN 0040-1951. Bibcode: 1988Tectp.151..363G.
- ↑ Ruiz Cruz, María Dolores; de Galdeano, Carlos Sanz (2005). "Compositional and structural variation of sudoite from the Betic Cordillera (Spain): a TEM/AEM study". Clays and Clay Minerals 53 (6): 639–652. doi:10.1346/CCMN.2005.0530610. Bibcode: 2005CCM....53..639C. http://openurl.ingenta.com/content/xref?genre=article&issn=0009-8604&volume=53&issue=6&spage=639. Retrieved 2018-10-20.
- ↑ Queffelec, Alain; Bellot-Gurlet, Ludovic; Foy, Eddy; Lefrais, Yannick; Fritsch, Emmanuel (2021). "First identification of sudoite in the Caribbean Ceramic Age lapidary craftsmanship". Gems and Gemology 57 (3): 206–226. doi:10.5741/GEMS.57.3.206.
attribution translated from :fr:Sudoïte
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