World mints are constantly striving to advance the technology of coin
security, to stay at least one step ahead of the counterfeiter.
Security measures also discourage fraud like clipping. Clippers
shave the plain edges of coins made from precious metal. One of the
oldest techniques for confounding the counterfeiter and the clipper
revolves around altering the coin’s “third side,” or edge. An enhanced
edge can have indentions, reeds, grooves, letters, or a pattern. And
the complexity of the edge an be further enhanced by a patterned rim
on both sides of the coin.
A “security edge” is a combination of edge alterations, such as
grooved and reeded together.
The high cost and difficulty associated with security edging means
that it is not common, but it is always interesting.
The edge has evolved over the centuries from a simple set of reeds
to discourage clipping to the complex varied security edges of the
20th century that also discourage counterfeiting.
The 1963 to 1971 rupee from Ceylon (now Sri Lanka) has an excellent
example of a security edge. The edge device of the 25-millimeter
copper-nickel coin is reeding cut in two by a beaded groove. By the
1980s, the security edge on the rupee had been replaced with simply a
Substituting is another type of fraud. In the 1990s, South Korean
500-won coins began showing up in Japanese vending machines made for
500-yen coins. The Korean coin had only 10 percent of the value of the
Japanese coin. Canceling the transaction forced the machine to return
a genuine 500-yen coin instead of the original 500-won piece.
As Japan has the highest number of vending machines per capita in
the world, this was a big problem. Vending machines were changed to
reject all but the new more secure 500-yen coins made beginning in
2000. The new 500-yen coin had helical ridges (spiraled reeds) on the
edge. The design included latent imaging, microlines thinner than a
human hair and invisible to the naked eye, and microdots and miniscule letters.
Poland also introduced a high-tech tough-to-copy ringed-bimetallic
coin in 2000 with multiple security features, the 2-zloty coin. The
edge was engraved, and the inscription 2000 LAT (2,000 years)
encircles the central design devices on the reverse. The latent image
date on the reverse changes back and forth between 2000 and 2001, and
another area of the design moves back and forth from stars to
lightning bolts. Horizontal and vertical microlines were added, as well.
China is widely regarded as a major international counterfeit coin
source, so collectors took note of its first “anti-counterfeiting
coin” in 2001. The 5-yuan coin commemorating the 90th anniversary of
China’s 1911 Revolution was equipped with several special features
like microprinting, microlines, and a type of latent imaging that the
Chinese called “invisible stealth patterns.”
In 2012, Malaysia totally revamped its coinage. The new 5-, 10-, 20-
and 50-sen coins all have different edges: plain, milled, and
indented. The two smaller denominations are silver colored and the two
larger, golden colored. The coins also use microlines for security and
are lightweight to make them easier to carry.
A version of the United Kingdom’s 2014 Britannia 1-ounce .999 fine
silver £2 bullion coin has a Chinese Lunar Year commemorative edge
design that is also meant to make it more secure. A pattern of tiny
galloping horses is repeated all the way around. The 2014 Britannia
Horse Privy mark silver bullion coin was issued for the Year of the
Horse just as its 2013 predecessor has a snake privy edge for the Year
of the Snake. Both animal-edged coins were immediately popular with
customers and it is likely that they will end up as part of a 12-year series.
Away from the edge
Canada has sought to protect its Maple Leaf 1-ounce silver bullion
coin with what the Royal Canadian Mint calls “micro-radial
The fine, perfectly spaced lines radiating across the surface of the
38-millimeter-diameter 2014 silver coin would be extremely difficult
to copy exactly. This feature may just be enough to discourage a
potential counterfeiter of the coin.
Derived from the Greek “drachma,” “dirham” is and has long been a
popular name for a monetary unit in many Middle Eastern nations.
Brunei began issuing silver and gold dirham bullion coins in 2013
that have a lot of symbolism and enhanced security features called “3D
The Jawi calligraphy on the reverse has microengraving around it.
The coins have a reeded edge, and rings of tiny eight-pointed stars,
an Islamic art symbol, are positioned just inside the raised rims on
The coins are issued in several denominations and sizes and are
already proving to be a popular wedding gift in the Middle East.