Mordenite is a naturally occurring zeolite mineral that is the seventh most common zeolite mineral globally, forming at low temperatures (≥100°C) in hydrothermal systems. In New Zealand, extensive deposits of mordenite are commonly associated with areas of hydrothermal alteration, particularly in the Coromandel and Taupo Volcanic Zones. Mordenite can form fibrous minerals, and several industries have the potential to disturb these naturally occurring mineral fibres, causing them to become aerosolised and potentially respirable. Nevertheless, mordenite is not currently known to be carcinogenic, in contrast to the fibrous zeolite, erionite. Indeed, erionite is a Group 1 carcinogen that has been linked to malignant mesothelioma due to its fibrous‐asbestiform shape and biodurability. In this study, mordenite from New Zealand is characterised and compared to erionite, using X‐ray powder diffraction (XRPD), scanning electron microscopy–energy dispersive spectroscopy (SEM–EDS), and an automated scanning electron microscope (SEM), in order to understand the extent, occurrence and morphology of mordenite in New Zealand. It also enables the evaluation of potential health implications, including whether these naturally occurring mineral fibres are respirable.
Hamilton et al. (Fri,) studied this question.