A rare reddish-brown mineral typically found as small spherical aggregates in association with manganese ore.
Akrochordite is a hydrated basic arsenate of manganese and magnesium, Mn₄Mg(AsO₄)₂(OH)₄·4H₂O. Crystal system: monoclinic.
1920s. From ancient Greek ἀκροχορδών acrochordon + -ite, after Swedish akrochordit, with allusion to the ‘wartlike’ spherical aggregates of the mineral.