Your First Line of Defense
Genuine US coins have precise specifications. Counterfeiters often get weight wrong — determined by metal composition. A digital scale ($15–$25) accurate to 0.01g is essential.
Standard Weights
- Lincoln cent (copper) — 3.11g | Lincoln cent (zinc) — 2.50g
- Nickel — 5.00g | Dime (silver) — 2.50g | Dime (clad) — 2.27g
- Quarter (silver) — 6.25g | Quarter (clad) — 5.67g
- Half dollar (silver) — 12.50g | Half dollar (clad) — 11.34g
- Morgan/Peace dollar — 26.73g | Silver Eagle — 31.10g
- $20 gold — 33.44g | $10 gold — 16.72g | $5 gold — 8.36g
Coins off by more than 0.20g are suspicious.
Diameter Testing
Digital calipers ($10–$20) measure to 0.01mm. Even 0.5mm off is a red flag.
Specific Gravity
Measures density relative to water. Nearly impossible to fake both correct weight AND correct specific gravity with the wrong metal.
- 90% silver — 10.34 | 22K gold — 17.15–17.75 | Copper-nickel clad — 8.92
Method: Weigh dry, weigh suspended in water, calculate SG = dry ÷ (dry − wet).
Up Next
This guide is for educational purposes. Where official standards, grading services, organization memberships, or legal requirements apply, consult the primary authority named in the references below or the relevant government agency.
Reviewed on January 28, 2026 by the US Coin Shows editorial team. Editorial policy
Official references and further reading
Frequently Asked Questions
How much should a Morgan dollar weigh?
26.73 grams (±0.10g). Significantly off = suspicious.
What is specific gravity testing?
Measures density relative to water. 90% silver = 10.34, pure gold = 19.32. Nearly impossible to fake both weight and SG with wrong metal.
Apply what you've learned