pectolite

noun

pec·​to·​lite

ˈpektəˌlīt

plural -s

: a whitish or grayish monoclinic mineral NaCa₂Si₃O₈(OH) consisting of a basic sodium calcium silicate occurring in crystal aggregates or fibrous masses (hardness 5, specific gravity 2.68–2.78)

Word History

Etymology

German pektolith, from Greek pēktos compacted (from pēgnynai to fix, fasten) + German -lith -lite

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