Carbonate of Manganese

This species has by most authors been confounded with Brownspar; and several who have separated it from that, have united with it the Lithoide Manganese of Siberia, a variety of Feldspar, a British specimen of which is figured in British Mineralogy, (tab, 536.) Brownspar sometimes occurs of a dull rose colour, hut never so bright as the rhomboidal crystals of Rose Manganese that accompany the Tellurium, Sulphuret of Manganese, Blende, Pyrites, &c. among Quartz: found at Nagyag, in Transylvania, (see tab. 91.) This variety, however, often contains much Carbonate of Lime even in the crystals; and in the amorphous part is so intimately mixed with Quartz, that it appears to form with it an homogeneous mass. The specimens from Kapnik appear to be very pure, and to contain no lime; thus proving the existence of the species. The larger specimen figured is from Nagyag: among the rose-coloured crystals of Carbonate of Manganese, are a few white rhombs of Brownspar, and some crystals of Quartz : the mass is probably a mixture of all three: Quartz is in various parts distinguishable in it in concentric coats. The black spots are Sulphuret of Manganese.

The lower specimen is also from Nagyag. The Carbonate of Manganese is in very much curved rhombs, and appears to be less pure than in the Upper specimen, forming an intermediate variety between it and Brown-spar, (Carbonate of Iron.) I have received lately from Scotland, Carbonate of Iron, of a pale pink colour, crystallized in rhombs, that approaches to the Manganese; it forms another connecting variety, and serves to prove that the species is not well circumscribed.

The following is the analysis of the pure variety, from Kapnik, by Lampadius:

The impure amorphous kind, from Nagyag, has been found by Kiaproth to contain,

There is probably another species of Manganese confounded with this, and differing from the Manganesian Feldspar above alluded to, containing Protoxide of Manganese combined with Silex: it is found at Kapnik.