noun
also tur·ma·line ˈtu̇rmələ̇n, ˈtu̇əm-, -məˌlēn
( -s )
Etymology: Sinhalese toramalli carnelian
1. : a mineral (Na,Ca)(Li,Mg,Fe,Al)(Al,Fe) 6 B 3 Si 6 O 27 (O,OH,F) 4 that consists of a complex borosilicate, fluoride, and hydroxide of aluminum, iron, magnesium, calcium, lithium, and sodium, that occurs usually in 3-, 6-, or 9-sided prisms vertically striated but sometimes in compact or columnar masses, that is strongly dichroic, piezoelectric, and pyroelectric, that shows double refraction but absorbs one of the rays, and that makes a gem of great beauty when transparent and cut (hardness 7-7.5, specific gravity 2.98-3.2) — compare schorl
2. : a very pale green that is bluer and darker than emerald tint or microcline green and bluer and deeper than celadon tint