Pyrite

Pyrite looks so much like gold that miners have been fooled by it for thousands of years, which earned it the name fool’s gold. Its perfect, geometric cubes are among the most satisfying shapes in the mineral world.

What it is

Pyrite is iron disulphide, FeS2, with a hardness of 6 to 6.5 on the Mohs scale. It is brassy yellow, with a metallic lustre and a greenish-black streak, which is one way to tell it from gold. Gold is soft, malleable and leaves a golden streak, while pyrite is brittle and leaves a dark one. It forms cubes, pyritohedra with five-sided faces, and rounded masses, in many types of rock and in coal seams.

It is found in many countries. The remarkably sharp cubes from Navajun in Spain are very famous among collectors, and Peru, Italy, the United States and China also have notable sources.

History and culture

The name comes from the Greek pyr, fire, because pyrite gives off sparks when struck against steel or flint. It was used to start fires, and in the sixteenth and seventeenth centuries it was the spark-producing part of wheel-lock firearms. Polished pyrite was used by the Inca and other Andean peoples, and by the ancient Maya, to make mirrors.

In jewellery, small pyrite pieces are often sold as marcasite, a term that has a long history in the trade, and marcasite jewellery was popular from the eighteenth century to the Art Deco era. Pyrite also turns up in lapis lazuli, where it forms the gold flecks.

What crystal traditions associate with it

In many crystal traditions, pyrite is associated with confidence, willpower and prosperity, reflecting its golden colour and its reputation as a stone with sparks. It is linked with the solar plexus in the chakra system, and with Leo in some zodiac lists, though sources vary. As with all stones, there is no evidence that it affects money, and these are symbolic associations.

How people use it

Cubes and clusters of pyrite are popular as desk ornaments and display pieces, and people hold a palm-sized piece during quiet reflection. Some use a pyrite sun, a disc with radiating crystals, as wall decoration. Small tumbled stones and beads are also sold.

Care and safety

Pyrite needs more caution than its hardness suggests.

• Keep pyrite dry. In damp conditions, it can oxidise and break down, forming sulphate salts and sulphuric acid, a process collectors call pyrite decay, which can damage the specimen and the things around it. Do not wash or soak pieces, and avoid storing them in humid rooms.
• Never put pyrite in drinking water, and never make an elixir with it. It can release sulphur compounds and iron.
• Do not swallow stones. Dust from grinding or scraping pyrite should not be inhaled, and it is best not to heat or burn pieces, since sulphur dioxide can result.
• Wash hands after handling rough pieces.
• Pyrite is brittle. Keep it away from other stones that could scratch it.

Fakes

Pyrite is sometimes confused with chalcopyrite, which is softer and more greenish-gold, and with actual gold. Brass and plastic pieces are also sold as pyrite. A streak test on an unglazed tile shows the dark streak of true pyrite, although it is best to keep polished pieces from being scratched.

Sourcing

Pyrite is found in many mining areas, and labour conditions vary. Ask where a piece came from if you care about provenance.

A note on health. Crystals are valued for beauty, meaning and ritual. There is no scientific evidence that they treat health conditions. If you are struggling with your health or mood, please speak to a doctor.

Frequently asked questions