a usually green or brown, hard, tetragonal mineral, CaMgAl(SiO)(SiO)(OH), usually found in metamorphic limestone; hydrous calcium magnesium aluminum silicate
See vesuvianite in American Heritage Dictionary 4
(vĭ-so͞oˈvē-ə-nītˌ)
noun
A green, brown, yellow, or blue metamorphic silicate mineral, Ca10Mg2Al4(SiO4)5(Si2O7)2(OH)4. Also called idocrase.