prehnite

noun

prehn·​ite

ˈprāˌnīt,

ˈpreˌ-

plural -s

: a pale green mineral Ca₂Al₂Si₃O₁₀(OH)₂ that occurs in crystalline aggregates having a botryoidal or mamillary structure but only rarely in distinct crystals and that is a basic calcium aluminum silicate (hardness 6–6.5, specific gravity 2.80–2.95)

Word History

Etymology

German prehnit, from Colonel Van Prehn 18th century Dutch officer who brought it from the Cape of Good Hope + German -it -ite entry 1

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