tephroite

[ tef-roh-ahyt ]
/ ˈtɛf roʊˌaɪt /

noun

a mineral, silicate of manganese, Mn2SiO4, occurring in orthorhombic crystals.

Origin of tephroite

1865–70; < German Tephroit < Greek tephró(s) ash gray + German -it -ite1
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019