dkns

Dickinsonite and Arrojadite - a comparison of specimens

Dickinsonite and Arrojadite have always been a special interest of mine. Arrojadite was named for a Brazilian mineralogist and, as an iron-rich minerals is found with other iron-rich minerals such as triphylite, heterosite, and siderite. Dickinsonite was named for a mineral collector from Connecticut and is found with other manganese minerals such as lithiophilite or rhodochrosite, although there is an exception as one of the associations illustrated here is with loellingite. (Loellingite probably partitions Fe >>>Mn and possibly accounts for the seeming inconsistency.). (Incidentally, there are no know photographs of Rev. Dickinson's friend, Abijah N. Fillow who owned the quarry. Fillow was also station master at the Redding Railroad station in the 1870's and 1880's. Perhaps the railroad historians may find something?