326 manganese. Second Subspecies. Foliated Black Manganese-Gre. Blattncher Schwarzbraunsteinerz, Hausmann. Verhiirtetes Schwarzbraunsteinerz, Reuss, b. iv. s. 463. Id. VftQ 1 ’ o'? 6 '-' S ’ ®^ ttr * c ^ e Manganschwarze, Haus. ' ’ „ Blattncher Schwarz Braunsteinerz, Haus. Handb. 293. External Characters. ^ Its colour is intermediate between brownish-black and iron-black. i It occurs massive, disseminated, and crystallised in elongated acute double tour-sided pyramids, which are small and very small, and aggregated in rows. ,. Surface of the cr ystals is seldom smooth, and shining or glistening, generally drusy, or rough and dull, nternally lt as intermediate between shining and glis- in g 5 and the lustre is adamantine. sinplp 6 ! fraCtUre ' S S enera] l v imperfect foliated, with a diated ° ^ ^ ^ sometimes inclining to diverging ra nted, sometimes to uneven. edged 6 fragments are indeterminate angular, and blunt- It occurs in small and i T . d nne granular concretions, lt is opaque. It affords a reddish-brown dull streak. It is semi-hard. It is brittle. It is easily frangible. It is heavy. Gcogmstic