What is "akrochordite"

n. (context mineral English) A monoclinic-prismatic reddish brown mineral containing arsenic, hydrogen, magnesium, manganese, and oxygen.

Akrochordite is an exceptionally rare hydrated hydrous arsenate mineral of the formula (Mn,Mg)(AsO)(OH)4HO and represents a small group of rare in the nature manganese (Mn) arsenates and, similarly to most other Mn-bearing arsenates, possess pinkish colour. It is typically associated with metamorphic Mn deposits.