Pyrite and Galena are considered to be sulfide minerals but they have some differences. One of the main differences is their chemical formula. For Pyrite, this is FeS2 while for galena, it is PBS. The colors of these two minerals may also differ. Galena may have a gray color and the shade may range from dark to light. Pyrite is known to have a similar color to brass.
This explains why there are some people who assume that Pyrite seems to be “fool’s gold.” People may believe that they have gold only to find out that they have pyrite instead. The average density of these sulfide minerals is also different.