Nodules of agate or opal in permian basalt (so called melaphyry) of Malužiná beds in Ipoltica group. Choč nappe (Hronic unit) Western Carpathians. Nodules, which are fillings of empty cavities, are result of hydrothermal postvolcanic activity. Sample from Geological institute of Dionýz Štúr in Bratislava.
<a href="//commons.wikimedia.org/wiki/User:Pelex" title="User:Pelex">Pelex</a>
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