The story
From Heuland + -ite after British mineral collector John Henry Heuland (1778-1856).
Etymology from Wiktionary, CC BY-SA 4.0.
heulandite
Today it means: A common mineral of the zeolite group with monoclinic crystals, the most usual form being heulandite-Ca (Ca,Na)₂₋₃Al₃(Al,Si)₂Si₁₃O₃₆·12H₂O. Full definition →