NOTE: the apparent surface flaws on this specimen are not there in person - they are just photo artifacts; in person, the surface is polished and glassy and there are no dull spots or lines as the pic implies). Elsewhere in this set of auctions, we have a goethite and mentioned that this mineral (basically, rust) can take on all sorts of forms. Here, it is goethite lining the cavity deep in the interior of the vug, underneath a layer of agate that gives this fire agate its internal form under the gem silica itself! This is rare and precious material. This is so pretty, though, it should remain a mineral specimen. This is an intense and beautiful piece in person!