Gemstone Glossary

Pyrite

Pyrite is a shiny golden yellow colored mineral with a metallic luster. The name comes from the Greek word meaning "a stone which strikes fire". This is due to the sparking produced when a lump of Pyrite strikes iron. Pyrite is often mistaken for gold, however the two are quite different and it is not that difficult to distinguish one from the other. Pyrite grains are lighter and tougher than gold, and has broken faces, properties that are not normally found in gold. Thus only a fool would mistake it for gold, which is why Pyrite is also known as "Fool's Gold".

Pyrite is the most common member of the Pyrite group of minerals. The group is composed of minerals with a similar isometric crystal structure and related chemistry. While this is actually a fairly large group, only Pyrite is common and only a few other members are even recognized by experienced collectors.


Pyrite is composed of iron sulfide (FeS2). It has a hardness of 6 - 6.5 on the Moh’s Scale with a Refractive Index of 5.1. Occurrences of Pyrite have been reported worldwide. Some of its major deposits are: USA, Peru, Germany, Russia, Spain, and South Africa. As it is found in almost every possible environment, Pyrite has a vast number of forms and varieties. The mineral has been found in single cube, intergrown cubic twins, mass of crystals, and dollar forms.

Industrially, although Pyrite is common and contains a high percentage of iron, it has never been used as a significant source of iron such as hematite and magnetite. Pyrite is not as economical as those ores, possibly due to their tendency to form larger concentrations of more easily mined material.

Pyrite was polished by the Native Americans in early times and used as mirrors. Today, Pyrite is used as an ornamental stone, as well as a very popular specimen for the amateur collector. It is sometimes used as a gemstone by being faceted and polished for use as a secondary jewel in a ring, necklace, or bracelet.