Laurie Meyers, age 11, of Lethbridge, Alta., Canada, for her question:

WHAT IS THE DIFFERENCE BETWEEN REAL GOLD AND FOOL'S GOLD?

Sad to say, all that glitters is not gold. Even though a substance may look like gold, it just might be a compound of iron and sulfur, called pyrite, or a compound of iron, sulfur and copper, called chalcopyrite. Both of these tricksters are called fool's gold mainly because inexperienced prospectors use to mistake them for real gold. The early colonists at Jamestown made this error and so did an unfortunate ship captain that carried an entire shipload of the worthless mineral back to England.

Pyrite, or iron pyrites, can be distinguished from real gold by a number of simple tests. Pyrite is quite brittle and will shatter when hit with a hammer, whereas gold simply flattens out. Real gold may be heated until it melts. Fool's gold, however, will sizzle, smoke and give off an unpleasant odor. When rubbed on a piece of unglazed porcelain, pyrite leaves a greenish black streak, while gold leaves a yellow streak. Scientists who study rocks could give us a number of other differences, but perhaps the biggest one is that real gold is composed only of atoms of gold. Fool's gold is composed of atoms of iron and sulfur, or iron, sulfur and copper, and contains no gold at all.