Minerals that resemble gold
“All that glitters is not gold” is a well-known saying. Pyrite and chalcopyrite are two minerals that resemble gold, and they are often called “fool’s gold”. The difference is that gold is much heavier, softer, and has a higher tenacity than the other two. Pyrite cannot be scratched with a knife, and often has a slightly paler colour than gold. Chalcopyrite can be scratched with a knife, but unlike gold it is brittle, and this will be detected by a scratch test. In addition, the knife will leave a dark greenish streak. Gold is very easily scratched with a knife, and the streak is shiny yellow.