Stilbit-Ca z amfibolitového kamenolomu Markovice u Čáslavi (Česká republika)
Ivana Jebavá, Jaroslav Heřmánek, Petr Pauliš, Lukáš Zahradníček
Stilbite-Ca was found in the active Markovice amphibolite quarry near Čáslav (Czech Republic). It crystallizes there as white, yellowish to reddish vitreous aggregates with columnar crystal shape, about 1 mm in the size. The crystals grow in the prehnite pocket which has about 5 cm in diameter. Stilbite-Ca from the Markovice quarry has exceptional contents of BaO (2 wt. %), which has not been published for minerals of stilbite series. The samples were studied by the PXRD and EDX analysis. The unit-cell parameters refined from X-ray powder data are: a = 13.622(9), b = 18.229(8), c = 11.269(7) Å, β = 127.94(2), V = 2207(2) Å3.