Native Copper

Perhaps this formation would never have been expected in Native Copper by the tyro in Mineralogy; and it is indeed very scarce. The rounding branches irregularly disposed, inosculating with their bluntish terminations and rugged rusty appearances 3 might be taken at first sight for a number of pieces of Iron wire aggregating so confusedly by means of rust: however, in colour it approaches to Copper, and may by scraping be easily distinguished, having the softness and red metallic lustre. It is rather remarkable, that the branches, if I may so call them, are sometimes so much coalesced as to join apparently in a continuous manner; at others they seem attached, as if pressed one against another and stuck together; and some parts of the sides and ends terminate as if they once had been joined to others, some being blunt and roundish, and others having a small concave disk.

I have placed another branched specimen, having the branches six-sided and somewhat irregularly cut, resembling an endeavour to do it with a knife, and so are somewhat scalloped, partly concave and generally rather flattish, with two sides broader than the rest; see the right hand magnified figure at lne bottom.

I have placed another peculiar ramification at the bottom on the left hand, showing more of the nature of structure depending on the order of the crystallization, more or less zigzag or feathered, which is shown more distinctly in the magnified figure. The whole are very small, but indicate the rhomb, tab. 216, and the dodecaedron, tab. 25, which are almost recognisable: the rhombic accumulation is pretty evident, and the angles of the zigzag appearance are the corners of the rhombs. Moss Copper generally belongs to this variety.

The specimens are from Cornwall, but the upper one is the most rare: such are much valued.