# Does pyrite retain the magnetic properties of its element iron?

You are walking in the mountains and pick up what looks like a nugget of gold. You're aware that fools gold (iron pyrite, $\ce{FeS2}$) exists. Create an experiment to test if this is pure gold or iron pyrite.

The simplest thing I could think of is to do a magnetic test on the assumption that if it was fools gold it would be attracted to a magnet due to the presence of iron. A quick google search reveals this to be true but I have a sneaky suspicion that I got lucky in assuming, because there is iron in $\ce{FeS2}$ the compound will be magnetic.

I'd like to know if chemical compounds retain the properties of their individual elements or if the compound gains completely new properties some of which may or may not be properties of the elements.

• As a general rule, compounds do not retain the properties of their elements. A classic example is NaCl, as discussed here – bon Sep 17 '15 at 9:26
• Simplest way is density - pyrite is about 4 times less dense than gold, lighter than pure iron. – Mithoron Sep 17 '15 at 10:21