Mark Smith, age 8, of Lakefield, Ontario, Cananda, for his question:

Does fool's gold have any value?

It was called fool's gold because miners sometimes mistook it for real gold. Actually it is a mineral compound of iron and sulphur. It has the shiny yellow luster of real gold. Sometimes it is found in the shape of a handsome cube with neatly sliced corners that give it 24 smooth, straight sides. Long ago, the Indians would rather find a neat cube of pyrite than a bumpy nugget of gold. The gold was only good for ornaments. But an Indian could use a bit of pyrite to strike a spark to light a fire.

Nowadays, fool's gold is not very valuable. It may be used to make sulphuric acid and to perform other useful work in industry. But it is a very plentiful mineral. We can find all we need of it in the ground and plenty more besides. Pyrite is useful, but the earth has so much of it that it may never become costly or very valuable.