This dramatic, sculptural specimen of Flos Ferri—stalactitic cave aragonite—from the famous Styrian Erzberg iron mine in Austria exemplifies the bizarre, coral- or Hydra-like growths for which this varietal is known. Formed in ancient siderite-rich caves, the snow-white aragonite branches into intricate, finger-like or arborescent shapes that seem to defy gravity. Flos Ferri, Latin for “flowers of iron,” is a misnomer in chemical terms, as aragonite contains no iron, yet the name has long been associated with this distinctive form due to its occurrence in iron-rich environments. This classic example from one of the world’s most iconic localities showcases the beauty and peculiarity of this rare and collectible aragonite habit.
