Oxide of Manganese

In tab. 86. of this work we have figured a rare specimen of Oxide of Manganese in columnar crystals. The present amorphous specimen is curious on account of the variety which it exhibits. It is supposed to be mostly Oxide of Manganese in different states, white, brown, and black; and the manner of its mixture adds to its beauty. The specimen is in the possession of Mr. Rashleigh, who received it from Devonshire. I have been favoured with specimens of red Manganese from the same place, where there is a great variety. Besides Oxide of Manganese this specimen contains in the whiter parts a tolerable proportion of Carbonate of Lime, which in some is crystallized like Pearl Spar, tab. 19.