Min. [Named after Mr. Braun of Gotha (Dana).] An anhydrous oxide of manganese, a brittle dark brownish-black mineral occurring both crystallized and massive.
1839. Penny Cycl., XIV. 380/2. Braunite.… Before the blow-pipe melts and effervesces slightly with borax.
1869. Roscoe, Elem. Chem., 233. Manganese sesquioxide … occurs in nature as the mineral braunite.
