Erionit-Ca z Michlova vrchu u Provodína, jv. od České Lípy (Česká republika)
Michal Řehoř, Ivana Jebavá, Jiří Svejkovský, Zdeněk Dvořák, Oldřich Janeček, Miroslav Radoň, Petr Pauliš
An interesting zeolite mineralization with rare erionite-Ca was discovered at the Michlův hill (NE of Provodín, SE of Česká Lípa, Czech Republic), which is formed by Tertiary volcanites penetrating a formation of Upper Cretacerous sediments. The erionite-Ca forms snow-white aggregates consisting of very soft fibers or brush-like aggregates with the diameter up to 2 mm in rock cavities. The refined unit-cell parameters for erionite-Ca are: a 13.257(5) Å, c 15.0568(2) Å and V 2291.6(9) Å3. Heulandite-Ca, phillipsite, chabazite and calcite were found in association with studied erionite.