1: 1. Study historical coin designs. 2. Examine the weight and size carefully. 3. Check for any inconsistencies in the details.

2: 4. Research the minting process used. 5. Verify the authenticity of the mint mark. 6. Look for signs of wear that match the coin's age.

3: 7. Examine the edges for signs of re-etching. 8. Inspect the surface under good lighting. 9. Utilize a magnet to test for counterfeit metals.

4: 10. Familiarize yourself with common counterfeit features. 11. Seek professional opinions from coin experts. 12. Beware of suspiciously low prices.

5: 13. Research the specific coin's history and variations. 14. Understand the market demand and rarity. 15. Compare your coin to authenticated examples.

6: 16. Watch out for altered dates or mint marks. 17. Countercheck against reputable online sources. 18. Inspect for unnatural or uneven toning.

7: 19. Avoid purchasing from unverified sources. 20. Consider coin authentication services. 21. Beware of "too good to be true" deals.

8: 22. Observe for signs of reproduction, such as casting marks. 23. Check for irregularities in the edge inscription. 24. Trust your instincts - if something feels off, it probably is.

9: 25. Keep abreast of new counterfeiting techniques. 26. Verify the coin's weight against reliable sources. 27. Learn from experienced collectors and numismatic associations.