Ricerc@Sapienza

A multi-methodological approach, based upon field investigation, morphological characterization, chemical analysis and structure refinement was applied to different samples of fibrous offretite, a new potentially hazardous zeolite recently discovered in northern Italy. Their morphology ranges from stocky-prismatic to asbestiform. All the investigated fibers may be considered as "inhalable", and they are well within the range of the "more carcinogenic fibers" regarding diameter.

The thermal behavior of a woolly erionite-K sample (Lander County, NV, USA), chemical formula (Ca2.03 Na0.73 K2.52 Mg0.26)[Al8.22 Si27.78 O71.80 ]·35.94H2 O, was investigated in the 303–1173 K thermal range by in situ X-ray powder diffraction. Present data suggest a general thermally-induced volume contraction whose magnitude increases as(formula presented) ratio becomes smaller. An inverse correlation between(formula presented) ratio and Tdehydr is observed because higher(formula presented) ratio values are associated to lower dehydration temperatures.