Carbonate of Iron, Sphærosiderite

Sphærosiderite, so named from its globular form, is a remarkable variety of spathose Iron ore. The spheres which frequently intersect and unite with each other, are composed of diverging radii, and exhibit the foliated fracture, characteristic of the species; they are contained in the hollows of a mass, composed principally of the same substance. Professor Stromeyer, to whom I am indebted for specimens, has found it to be pure carbonate of Iron: it is found at Steinheim, near Hanau.

A fibrous variety of the same substance has been sent me by Mr. Rashleigh, from Cornwall, since the conclusion of British Mineralogy: it occurs in veins traversing chlorite slate, in Tincroft mine. I have added a figure of it.