Fool’s Gold vs. Real Gold

Do you know the difference?

It’s St. Patrick’s Day, and while leprechauns may be searching for pots of gold, not everything that shines is the real deal!

One of the most common gold lookalikes is pyrite (FeS₂), better known as “fool’s gold.” While pyrite has a brassy yellow color and metallic luster, one of the biggest giveaways is its cubic crystal structure. Pyrite naturally forms in cubes of varying sizes, while gold is never cubic—it occurs in irregular, rounded nuggets or flakes.

🧐 How else can we tell the difference?
✅ Density: Gold is much heavier (19.3 g/cm³) than pyrite (4.9-5.2 g/cm³).
✅ Hardness: Gold is soft (2.5-3 on the Mohs scale), while pyrite is much harder (6-6.5).
✅ Chemical Tests: Gold doesn’t react to acids, but pyrite will fizz in nitric acid.
✅ Analytical Methods: We use ICP analysis and fire assay to determine actual gold content.

Although pyrite itself isn’t valuable, it can sometimes contain trapped gold within its structure, requiring specialized processing like roasting or pressure oxidation to unlock the gold. So, if you ever find a shiny rock with cube-like formations—don’t be fooled, but don’t discard it too soon either!

Check out this picture of pyrite’s natural cubic structure—a clear difference from how gold appears in nature! 🏆