Original paper
Thermal behaviour of analcimes from two different genetic environments
Giampaolo, Ciriaco; Lombardi, Gianni
European Journal of Mineralogy Volume 6 Number 2 (1994), p. 285 - 290
18 references
published: Mar 28, 1994
manuscript accepted: Dec 14, 1993
manuscript received: Jul 5, 1993
DOI: 10.1127/ejm/6/2/0285
Abstract
Abstract: Hydrothermal analcimes (H-type) and leucite-derived analcimes (X-type) from different Italian localities have very similar XRD patterns but different thermal behaviours. Dehydration of the H-type analcime gives a DTA peak between 350° and 370°C, whereas the X-type yields a wide band between 235° and 320°C. Activation energy in the H-type analcime is 6.9-7.1 kcal/mole, whilst in the X-type it is 5.3 kcal/mole. Such results are of relative value only because they are derived from non-isothermal runs and are strongly affected by the chosen method of calculation. Both DTA and TG methods provide evidence for a difference in the H2O bonding energies within the analcime structure crystallized in different genetic environments.
Keywords
Hydrothermal analcimes (H-type) and leucite-derived analcimes (X-type) from different Italian localities have very similar XRD patterns but different thermal behaviours. Dehydration of the H-type analcime gives a DTA peak between 350° and 370°C • whereas the X-type yields a wide band between 235° and 320°C. Activation energy in the H-type analcime is 6.9-7.1 kcal/mole • whilst in t