From Sailauf, Germany
 
In July 2006 there was a find of lustrous black crystals with triangular faces on carbonate crystals. It
looked similar to Braunite but unlike to Braunite small crystals are translucent reddish-brown. Analysis 
showed that these crystals are very close or even identic to Arseniosiderite. In fact I don't know any 
locality worldwide where Arseniosiderite occurs in such well shaped triangular black crystals and still
there is a little doubt if it is really Arseniosiderite.
 
Dimensions 1.8 0.7 1 cm