Mammillated and Stalactitic Oxyde of Manganese
Manganese is worthy of being known in all its appeal ances and varieties, as an useful and valuable article to the Bleacher and Printer. It is abundant, in many places, yet those who have seen it in the greatest abundance, perhaps have never seen it either mammillated or stalactitical; we, therefore, show it in a mammillated or partly staJactitical form, as in the upper figure, bubbling as it were in rounded knobs, and yet breaking with a smooth, somewhat conchoidal fracture. The lower figure exhibits a determined stalactite, with a little drop at the bottom; it seems to have accumulated with moisture, either in drops, or divided so as to form a sort of coating, more or less continuous.
The upper one is moderately dense, but the lower one is lighter to the hand, and I have some which feels like cork in the hand, with a bright and dark fracture, and another specimen as light, dull, smooth, and brown internally. These specimens mostly come from Mendip Hills.