-təˌnīt noun
( -s )
Etymology: William H. Wollaston died 1828 English chemist and physicist + English -ite
: a triclinic mineral CaSiO 3 of a white to gray, red, yellow, or brown color consisting of native calcium metasilicate occurring usually in cleavable masses and sometimes in tabular twinned crystals (hardness 4.5-5, specific gravity 2.8-2.9) — called also tabular spar