What Is Pyrite?
Pyrite, often called “Fool’s Gold,” is an iron sulfide mineral (FeS₂) with a shiny golden luster. While it looks like gold, pyrite is harder, lighter, and forms in distinct crystal shapes such as cubes. Collectors prize it for its beauty, but fakes and imitations are common in today’s market.
Simple Tests to Spot Real Pyrite
1. Streak Test
Scratch your specimen on an unglazed ceramic tile:
- Real pyrite leaves a greenish-black streak.
- Gold leaves a yellow streak.
- Brass or fakes may leave no streak.
2. Hardness Test
On the Mohs scale, pyrite rates 6–6.5.
- It can scratch glass.
- Gold, much softer, cannot.
3. Appearance
- Real pyrite: pale brass-yellow, shiny metallic cubes or clusters.
- Gold: deeper yellow, irregular forms.
- Imitations: painted stones or overly perfect crystals.
4. Weight
Gold is significantly heavier than pyrite. A piece that feels light for its size is likely pyrite.
5. Acid or Heat Test
- Pyrite may fizz slightly with weak acid or release a sulfur smell when heated.
- Gold shows no reaction.
Common Imitations
- Chalcopyrite: softer, tarnishes easily.
- Marcasite: brittle, prone to crumbling.
- Dyed quartz or brass: used in fake jewelry.
Tips for Buyers
- Buy from reputable mineral dealers.
- Check for natural imperfections; perfectly uniform clusters are often synthetic.
- If possible, perform a streak or hardness test before purchase.
FAQs
Q: What’s the fastest test?
The streak test—pyrite leaves a dark streak, gold leaves a yellow one.
Q: Can pyrite be used in jewelry?
Yes, but it’s brittle, best for pendants or display pieces.
Q: Is all “marcasite jewelry” real marcasite?
No—most is actually polished pyrite.
Conclusion
Pyrite is a fascinating mineral, but imitations are everywhere. By using simple tests like streak, hardness, and weight, you can easily tell if your specimen is the real deal. Always buy from trusted sellers to avoid fakes and enjoy the beauty of genuine pyrite in your collection.
👉 Learn more about minerals at the Mineralogical Society of America