Suboxide of Uranium

The mineral before us, is that combination of Uranium in which Klaproth first discovered the metal he found afterwards in a higher state of oxidizement in Uranite. It may be known from all other minerals by its deep brown black colour, hardness, opacity, dull lustre, the absence of a regular foliated structure, its weight, the spec. grav. varying from 6.3785 to 7.5. and its infusibility.

One specimen was given me by Prof. Strömeyer, the other by Mr. Herman: they are both from Johanngeorgenstadt: the matrix is chiefly brown Iron-stone and Iron Pyrites: one is mixed with Cobalt and Blende, the other with Galæna.

A variety of Asphaltum accompanies the Uranite in some of the Cornish mines, which has been taken for the suboxide of Uranium, but it may soon be recognized by its softness and combustibility.