hydrous calcium aluminum iron silicate, a yellowish-green to black mineral, Ca(AlFe)SiO(OH), found as monoclinic crystals, grains, or masses and sometimes used as a gem
Origin of epidoteFrench épidote ; from Classical Greek epididonai, to give besides, increase ; from epi-, over + didonai, to give (see date): so named by R.-J. Haüy (1743-1822), French mineralogist; from the enlarged base of some of the crystal forms
A lustrous yellow, green, or black mineral, Ca2(Al, Fe)3(SiO4)3OH, commonly found in metamorphic rock.
Origin of epidoteFrench épidote, from Greek epididonai, to give in addition, increase (from the greater length of its crystals compared with those of related minerals) : epi-, epi- + didonai, to give; see dō- in Indo-European roots.