Podrobnosti záznamu

Název
    Bibliography of Hibschite, a Hydrogarnet of Grossular Type
Údaj o odpovědnosti
    Franz Pertlik
Další názvy
    HIBSCH 2002 Symposium, Teplá near Třebenice, Ústí nad Labem, Mariánské Lázně, Czech Republic, June 3-8, 2002 (Variant.)
Autor
    Pertlik, Franz
Jazyk
    anglicky
Zdrojový dokument - seriál
    Geolines
Svazek/č.
    Vol. 15
Strany
    p. 113-119
Rok
    2003
Poznámky
    3 obr., 4 s. bibl.
    il.
    Zkr. název ser.: Geolines (Praha)
Předmětová skupina
    bibliografie
    granáty
    grosulár
    krystalochemie
    nomenklatura
    syntéza minerálu
    vulkanity Českého středohoří
Geografické jméno
    ČR-Čechy
    Gruzie
    Itálie
    Nebočady (Děčín)
    USA-California
    Ústí nad Labem
Klíčové slovo
    Bibliography
    Grossular
    Hibschite
    Hydrogarnet
    Type
Abstrakt (anglicky)
   Crystalline representatives of an isomorphous series from Ca3Al2(SiO4)3 (grossular) to Ca3AI2(OH)12 (katoite)are widespread natural phases described from a lot of mineral localities. Members of this series with a substitution of (SiO4)-tetrahedra <50 per cent by (OH)-groups and formula Ca3Al2(SiO4)3-x(OH)4x and x within the range O < x < 1.5 are specified as hibschite, while members with a substitution of 50 per cent to 100 per cent are specified as katoite. A substitution of Al by Fe3+ up to 50per cent does not change the nomenclature. The atomic arrangement, determined by X-ray and neutron diffraction data as well as IR-spectroscopic investigations confirmed the position of the (OH)-groups substituting the (SiO4)-tetrahedra. In addition to the substitution of (SiO4)-tetrahedra by (OH) groups, the presence of hydroxyl groups in other positions of the crystal structure was presumed in some hydrogarnets derived frommetamorphic rocks and described as 'defective garnet structures'.
   Various reasons for anomalous optical behaviour of 'cubic' garnets are discussed in literature [e.g., the presence of(OH)-groups distributed in a noncubic manner]. Annealing experiments indicate that the incorporation of hydroxyl groups is not the primary reason for this behaviour: cation ordering on octahedral positions may play an important role, too. Hydrothermal syntheses revealed crystalline compounds within the whole range from grossular to katoite in dependence to the proportion of the inserted elements. These formations are in accordance with the widespread occurrences of minerals of the whole hydrogrossular series as hydrothermal formations in calcareous environments
Přispěvatel
    Česká geologická služba
Kód přispěvatele
    ČGS (UNM)
Zdrojový formát
    U
Datum vložení
    15. 6. 2007
Datum importu
    8. 8. 2012