Mineralogy of "eye-like" opals from Nová Ves near Oslavany (Moldanubian zone, Bohemian Massif)

KONÍČKOVÁ, Šárka; Zdeněk LOSOS; Vladimír HRAZDIL; Stanislav HOUZAR a Dalibor VŠIANSKÝ. Mineralogy of "eye-like" opals from Nová Ves near Oslavany (Moldanubian zone, Bohemian Massif). In Joint 5th Central-European Mineralogical Conference and 7th Mineral Sciences in the Carpathians Conference. 2018.

Základní údaje

Originální název

Mineralogy of "eye-like" opals from Nová Ves near Oslavany (Moldanubian zone, Bohemian Massif)

Autoři

KONÍČKOVÁ, Šárka; Zdeněk LOSOS; Vladimír HRAZDIL; Stanislav HOUZAR a Dalibor VŠIANSKÝ

Vydání

Joint 5th Central-European Mineralogical Conference and 7th Mineral Sciences in the Carpathians Conference, 2018

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Další údaje

Jazyk

angličtina

Typ výsledku

Konferenční abstrakt

Stát vydavatele

Česká republika

Utajení

není předmětem státního či obchodního tajemství

Označené pro přenos do RIV

Ne

Organizační jednotka

Přírodovědecká fakulta

Klíčová slova anglicky

eye-like concentric opal;quartz;mineralogy;weathering;serpentinite

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Anotace

V originále

The locality Nová Ves near Oslavany, situated in Moldanubian zone of western Moravia, represents the only known occurrence of zonal "eye-like" (concentric) opals in Bohemian Massif. This specific type of opal is characterized by a concentric zonal texture with white core ("eye"), brown massive translucent inner rim and locally also white porous outer rim. These opals occur in residual sediments in a small area along the contact of serpentinized peridotite and granulite. White and grey "eye" and brown inner zone contains mainly opal-CT. Quartz and moganite are present in part in white aggregates of the "eye" only. White outer rim of opals is composed of calcite with disseminated opal relics and this zone is younger as core and inner rim (calcite replaces opal). X-ray powder diffraction analyses proved presence of sepiolite admixture in brown part and accessory amount of sepiolite and chlorite in white rim.