PYRITE CUBES SPHALERITE
An outstanding specimen of Pyrite Cubes Sphalerite. Sparkling and aesthetic a great metal to add to your collection. These cube clusters are hard to get from this location. This specimen has been mounted on a perspex pad for enhanced display. The Pyrite cubes are striated and situated in twinned and stacked forms.
6.7cm x 3cm x 6.1cm, 144g.
Ninth of September Mine, Madan, Bulgaria.
Pyrite, Iron Sulfide FeS2.
Pyrite is the classic “Fool’s Gold”. There are other shiny brassy yellow minerals, but pyrite is by far the most common and the most often mistaken for gold. Whether it is the golden look or something else, pyrite is a favorite among rock collectors. It can have a beautiful luster and interesting crystals. It is so common in the earth’s crust that it is found in almost every possible environment, hence it has a vast number of forms and varieties.
Bravoite is the name given to a nickel-rich iron sulfide. It is closely related to pyrite but contains up to 20% nickel. Some mineral books treat it as a variety of pyrite. Pyrite is a polymorph of marcasite, which means that it has the same chemistry, FeS2, as marcasite; but a different structure and therefore different symmetry and crystal shapes. Pyrite is difficult to distinguish from marcasite when a lack of clear indicators exists.
Pyrite’s structure is analogous to galena’s structure with a formula of PbS. Galena though has a higher symmetry. The difference between the two structures is that the single sulfur of galena is replaced by a pair of sulfurs in pyrite. The sulfur pair are covalently bonded together in essentially an elemental bond. This pair disrupts the four fold symmetry that a single atom of sulfur would have preserved and thus gives pyrite a lower symmetry than galena. We have sold the Disc form called Pyrite Sun, Spheres formed of hundreds of squares, Cubes of near square, Octahedral crystal form and crystal cluster forms.