About Singapore Coins
The Third Series coins are minted on multi-ply plated steel, comprising a steel core electroplated with three layers of metals as follows:
- Nickel over copper over nickel for silver-coloured coins such as the 10-cent, 20-cent and 50-cent coins.
- Brass over copper over nickel for gold-coloured coins such as the 5-cent and the outer ring of the 1-dollar coin.
Note: As with all copper-based materials, brass will tarnish when it oxidises. Oxidation is a natural process and the rate at which the coin oxidises depends on its handling and the elements it has been exposed to. The tarnishing of the coin does not diminish its value or change its electromagnetic signature (EMS). They will continue to be accepted at banks and automated coin handling machines unless they are unfit for recirculation and subsequently removed.
- Sharp and defined relief of the design.
- Milled edges.
- Lettering and characters on both sides of the coin.
- Weighs within the standard tolerance of the gazetted coin specifications.
- A customised EMS for each denomination.
- EMS is used by most coin-operated machines to identify and verify if a coin is genuine.
For the Third Series $1 coin, visual security features include:
- Laser mark micro-engraving.
- The orchid-shaped laser mark of the Vanda Miss Joaquim, the national flower of Singapore, showing a dense micro-pattern of circles under magnification.
- Bi-metallic composition with a brass-plated outer ring and a nickel-plated inner circle.
- Counterfeit bi-metallic coins are usually made using paint instead of two different types of metals.
How to Identify Counterfeit Coins
- Uneven, poorly defined or worn off milling or edge patterns.
- Indistinct, not sharp or well-defined relief of the design, lettering and characters.
- Numerous pitmarks on the surface of the coin, which may also appear very porous.
- Different diameter, thickness and weight from the gazetted coin specifications.
- Misaligned orientation of the obverse and reverse designs.
For numismatic and commemorative coins, you may contact The Singapore Mint at 6566 2626.