a. A salt or ester of an arsenic acid; a compound containing one of the
three radicals in which arsenic has a +5 valence: ortho-arsenate, AsO4; meta-arsenate, AsO3 ; pyro-arsenate, As2 O7 .
b. A mineral characterized by pentavalent arsenic and oxygen; e.g.,
mimetite Pb5 (AsO4 )3 Cl . CF: vanadate
Dictionary of Mining, Mineral, and Related Terms