Szakáll Sándor - Jánosi Melinda: Minerals of Hungary (Topographia Mineralogica Hungariae 4. Miskolc, 1996)

lherzolites, but diopside, enstatite, and spinel may also be present (Fig. 66). In inclusions of sedimentary origin, a contact metasomatic assemblage (serpentine minerals, brucite, tobermorite, thaumasite, and hydrotalcite) exists. Hydrothermal and autopneumatolitic precipitates are common in blowholes. The first phase of formation was represented by the rockforming minerals augite, hornblende and plagioclase and the oxides magnetite, and ilmenite. Carbonates, calcite and aragonite, and zeolites, phillipsite, chabazite, natrolite, tetranatrolite, gonnardite, gmelinite and thomsonite crystallised later (Fig. 67 and 68). These zeolites, appearing in a variety of shapes and habits, are veritable ornaments of basaltic vesicles and blowholes. In the final stage of basaltic vulcanicity -