laumontite

noun

lau·​mont·​ite

variants or less commonly laumonite or lomonite

lōˈmän(t‧)ˌīt

plural -s

: a white monoclinic mineral CaAl₂Si₄O₁₂.4H₂O consisting of a hydrous calcium and aluminum silicate and having a vitreous luster that upon exposure to the air loses water, becomes opaque, and crumbles

Word History

Etymology

laumontite, laumonite alteration of lomonite, irregular from F. P. N. G. de Laumont †1834 French mineralogist + English -ite

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