This shiny, yellow mineral can look so like gold it has fooled many prospectors into thinking they have struck it rich. No
wonder, then, it is sometimes known as 'fool's gold'. It is among the most common of all minerals, found in almost every
environment. Indeed, any rock that looks a little rusty probably contains pyrite. It comes in a vast number of formsand varieties, but the most common crystal shapes are cubic and octahedral. One sought-after form is flattened nodules found in chalk, siltstone and shale called 'pyrite suns' or 'pyrite dollars'. The nodules are usually made of thin pyrite crystals radiating from the centre. Pyrite getsits name from the Greek for 'fire' becauseit can give off sparks when
struck- which is why it has been used tolight fires since prehistoric times. Although it is rich in iron, it has never been
usedas an iron ore. In the past, though, it was used