Pyrite the Impostor

       Pyrite, or iron pyrite, as it is sometimes called, is a heavy mineral that has a metallic lustre. Its chemical name is iron sulfide, which means that it is composed of iron and sulfur. Pyrite is usually a brassy yellow color, but weathering can cause pyrite to display red, purple, orange, and blue colors. Pyrites that exhibit all of these colors are often called "rainbow pyrites" because the layers of color remind people of a rainbow. Pyrite is famous for growing in cube-shaped crystals, but can also grow in "suns" where its crystals radiate outward from a single point to form a circular pattern of long, tapering, triangular crystals that look like sunbursts. Pyrite crystals can also from in strange geometric shapes that have been given the name "pyriohedra." These shapes have twelve pentagonal, or five-sided, faces. Pyrite cubes can be smaller than the head of a pin or larger than an American quarter. Small cubes are often found as crusts on other rocks or bunched together in massive lumps. Pyrite can also replace organic materials to make fossils in a process known as pyratizing. Pyratized ammonites are the most famous example of pyrite fossils, but others ar common as well. I have found pyratized crinoid stems and brachiopods.
       I'm sure a lot of people have heard the term "fool's gold" before. There are a few minerals that have been given this name, but the most common is undoubtedly pyrite. This is because pyrite is yellow in color, like gold. This is why I call pyrite the Impostor, because it is often mistaken for gold. However pyrite can be distinguished from gold by two simple methods. The first way to distinguish pyrite from gold is by the streak test. The streak test is a method used in mineral identification in which one scrapes the mineral in question against a piece of unglazed white porcelin leaving a streak. Each mineral has its own streak color, some streaks are a different color than the mineral that made them. Pyrite is yellow, but it has a green or black streak. Gold has a yellow streak. That test can easily determine whether or not a specimen is gold or pyrite. The second test is one that I have personally developed (I'm not sure if anyone else has done it before, but I don't think that I've ever seen it in a rocks and minerals book) I call it the rust test. Pyrite contains a great amount of iron in its composition and it will rust if it is exposed to too much water so, if you have a specimen that you think might be either gold or pyrite try dropping apiece of it in some water an allow it to sit for a while. It will usually rust after some time if it is in fact pyrite. A word of warning: the pyrite will most likely be ruined in this test!
     Pyrite has had varied uses over the years. When struck with a iron, pyrite will sometimes produce sparks. This is actually where pyrite's name originated. The name pyrite comes from the Greek word pyr, which means fire, referring to the sparks. Because of its tendency to spark it was once used as a component in a firearm. The wheelock gun had a iron wheel that would turn and rub against a piece of pyrite inside the firearm and ignite the powder when one pulled the trigger. I read that you can produce sparks from pyrite by striking it with flint. I have tried this and haven't had any luck so far. Pyrite has been used to make jewelry since ancient times and is still used a little today; all though it is quite brittle and must be cut very carefully. It is not very valuable as a gemstone so it's usually only used to make costume jewelry. In fact pyrite has more use in industry than in most other fields today. Because of its high iron content pyrite is used as an iron ore. Pyrite can also be used to make sulfuric acid because of its sulfur content. Unfortunately in some places where pyrite was mined for use in these industries, too much pyrite power was allowed into the environment and some natural chemical weathering produced some sulfuric acid, which made its way into the areas' water and damaged some of the local wildlife. Fine pyrite crystals are also sold to collectors.
      Pyrite is found all over the world in igneous, sedimentary, and metamorphic rocks. Some of the most obvious sources would be areas that are rich in sulfur and iron, like my home. I have found a few cubic crystals, two or three massive conglomerations of tiny cubes, and one crust. Areas around Detroit, Michigan, and Toledo, Ohio are also good localities in the USA in where pyrite can be found. On a rock-collecting trip that my church took to a location in Ohio near Toledo one rock hound found a conglomeration of cubes in which a lot of cubes protruded the specimen and were individually visible. Places where some of the best crystals can be found include, Spain, Peru, Italy, France, Mexico, and Italy. Because of its color, geometrically-shaped crystals, and history as "fool's gold' pyrite is truly an awesome mineral. I'm glad that our Creator has put it in so many places around the earth!