Pyrite’s chemical formula is FeS2, which is the same as the much rarer mineral, Marcasite. Even though these two have the same chemical formula, they both crystallize differently, causing them to be classified as different minerals. Sharing the same chemical formula causes these two minerals to be mislabeled, since their physical characteristics are so similar, and the only real way to definitively tell them apart is by complex analysis. http://www.minerals.net/mineral/pyrite.aspx
Pyrite is composed of Iron Sulfide, and sometimes contains trace amounts of …show more content…
Pyrite does not have a cleavage pattern, but has a conchoidal fracture pattern, a black with a hint of green streak color, and a brittle tenacity. Another prominent ID mark that Pyrite has is that when the exposed surfaces oxidize, a yellow-brown or iridescent film forms over these faces. Pyrite belongs in the simple sulfides group, and forms in all types of environments. The striking features of Pyrite are the hardness, how well the crystals are shaped, streak, heaviness, and color. Pyrite does not have a specific rock type, since it is Igneous, Metamorphic, and Sedimentary all at once.