Why Your Clad Coins Can Fool a Sigma Verifier (And How to Catch Them)

Altrukom Bullion Education

Why Your Clad Coins Can Fool a Sigma Verifier (And How to Catch Them)

At Altrukom Bullion, verifying physical precious metals is the foundation of everything we do. When testing silver coins, most stackers assume a quick scan on a precious metal verifier gives an immediate pass-or-fail answer. However, testing a 1964 90% silver Kennedy half dollar against a modern 2023 clad half dollar on the Sigma Metalytics Verifier Investor Edition reveals a surprising trick that catches many coin collectors off guard.

The Vending Machine Trap: Why Clad Passes Conductivity

When setting the Sigma Verifier to "90% Coin 1945–" and placing a 1964 silver half dollar on the sensor, the reading lands comfortably inside the green brackets. That is expected. But when placing a 2023 clad half dollar on the exact same setting, the reading also lands inside the green bracket.

This isn't a machine malfunction—it's historical engineering. When the U.S. Mint transitioned away from 90% silver in 1965, copper-nickel clad coins were specifically designed to match the electrical resistivity of 90% silver half dollars. This allowed new clad coinage to work seamlessly in vending machines and coin sorters without triggering rejections.

Exposing Clad with Multi-Stage Testing

Because electrical conductivity alone isn't enough to distinguish clad from constitutional silver, multi-stage testing is required. At Altrukom, we utilize the Sigma's dimension testing mode to measure electromagnetic density alongside physical thickness and diameter:

  • 1964 Silver Half Dollar: Fits perfectly between the green calibration lines on the screen during the dimension check (PASS).

  • 2023 Clad Half Dollar: Fails the dimension check immediately, with the reading falling completely outside the acceptable parameters (FAIL).

Protecting Your Stack with Altrukom

Relying on a single metric to verify precious metals leaves your portfolio vulnerable. To ensure absolute authenticity across your holdings, the experts at Altrukom Bullion recommend following a three-step testing routine:

  • Verify Weight: Cross-reference against standard specifications (12.50g target for 90% silver half dollars vs. ~11.34g for modern clad).

  • Check Dimensions: Use precision calipers or verifier dimension screens to confirm diameter and thickness match official mint profiles.

  • Test Density: Always combine resistivity checks with physical size and weight measurements.

Want to see this test performed step-by-step? Watch the full video demonstration on our official YouTube channel (@altrukombullion). To start building a 100% verified silver stack delivered directly to your door, visit ALTRUKOM.COM and explore our custom subscription plans today.

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