Portal de Periódicos da CAPES

Konyaite in Salt Efflorescence from a Tertiary Marine Deposit near Geelong, Victoria, Australia

1984; Wiley; Volume: 48; Issue: 4 Linguagem: Inglês

10.2136/sssaj1984.03615995004800040047x

1435-0661

A Shayan, C. J. Lancucki,

Building materials and conservation

Abstract Konyaite [Na 2 Mg(SO 4 ) 2 ·5H 2 O] was identified for the first time in Australia in salt efflorescences from a Tertiary marine deposit below exposed basalt flows at a quarry near Geelong, Victoria. Other soluble salts in the efflorescence were epsomite (MgSO 4 ·7H 2 O), gypsum (CaSO 4 ·2H 2 O), and halite (NaCl). Heating at 110°C converted the konyaite to a mixture of bloedite [Na 2 Mg(SO 4 ) 2 ·4H 2 O], loeweite [Na 4 Mg 2 (SO 4 ) 4 ·5H 2 O], and thenardite (Na 2 SO 4 ). Recrystallization at 23°C of the efflorescence dissolved in varying amounts of water indicated that epsomite and thenardite form from dilute solutions, whereas increasing amounts of konyaite recrystallize from the more concentrated solutions under faster evaporative conditions. The salts are transported to the basalt quarry site in river seepage or ground water from the neighboring marine deposits and are left on the exposed surfaces by evaporation.