Divergent groups of prismatic crystals are found in the basalt of Berufjördur near Djupivogr, Suður-Múlasýsla, Iceland and in the Deccan Traps near Pune in India; hence the synonym poonahlite for this species.
Möðrudalur is a farm settlement in Norður-Múlasýsla in Eastern Iceland, and the highest inhabited place in the country, at 469 m (1,539 ft) above sea level.