Money Musings

Extraterrestrial Coins

Published May 10, 2024 | 6 min read

By Ken Bressett

While it may be difficult to believe, some of our most popular coins hold a special secret: They may have been made from metal that originally came from some distant planet! Nickel and gold, for instance, are not indigenous to our world. They could only have been brought here in meteorites through some accidental celestial upheaval.

Nickel, as a coinage metal, is one of those unusual elements that deserves special attention. While seemingly common, it has long been called the devil’s copper or devil’s metal because the ore looks like copper, which was more valuable in ancient times. However, it was extremely difficult to extract from ore until the advent of the Bessemer converter in the mid-1850s.


About 95 percent of all meteorites contain iron-nickel (FeNi). Iron-nickel means that the metal is mostly iron but contains 4 to 30 percent nickel, as well as a few tenths of a percent of cobalt. Iron-nickel alloys in meteorites also have high concentrations (by terrestrial standards) of rare metals like gold, platinum, and iridium. Deposits of gold on our planet share the same origin, and they’re believed to have arrived here about the same evolutionary time.

An Out-of-this-World Ancient Coin

One of the most famous examples of verifiable extraterrestrial coinage began in ancient Bactria. What makes their coins unique is that they are made of copper-nickel. No other coin made before that, or for 2,000 years thereafter, was ever made of that metal! They used an alloy of 75-percent copper and 25-percent nickel, the same used in modern-day U.S. 5-cent coins.

The typical Bactrian coin type shown here is attributed to Agathocles Dikaios, the Buddhist Indo-Greek king of Bactria who ruled from 185 to 175 B.C. It is a copper-nickel double unit, 23mm in diameter, and weighs 7.51g grams. The mystery is where the metal came from and why and how these coins were made from this difficult-to-manage metal.

Stylistically there is nothing unusual about this coin. It shows a draped bust of Dionysus facing right and wearing an ivy wreath with a thyrsus (a staff or spear) over his shoulder on the obverse. The reverse shows a panther at right touching a vine with a raised paw. Above and below are the words ΒΑΣΙΛΕΩΣ ΑΓΑΘΟΚΛΕΟΥΣ (“King Agathocles”). The exergue features a monogram.

At a time when metallurgy was still in its infancy, the knowledge that nickel alloyed with copper was strong and more durable was a closely guarded secret. Chinese alchemists discovered the alloy sometime around 300 B.C. The bright reformulated metal was at first thought to be silver. Eventually, the superior metal was used almost exclusively to make swords and other weapons, thus giving the Chinese armies a much-feared secret weapon.

In the late 2nd century B.C., several Bactrian kings issued coins made of a copper-nickel alloy instead of copper or bronze. The reason for issuing those unusual coins remains a matter of conjecture. This most likely indicates that the material either came from trade with China or experiments with metal that came directly from outer space.

At that time, nickel ore was considered rare. When alloyed with copper, it became very hard. However, Greek furnaces were not hot enough to properly melt nickel, so their coins tended to be pitted and grainy.

Copper-nickel objects were also known and used in ancient Egypt during King Tutankhamun’s reign in the 14th century B.C., as seen in the carefully crafted dagger that was buried with him. This dagger could only have been made from a meteorite at a time when iron was considered more valuable than gold, and the revered metal was called “iron from the sky.”

Nickel Goes Mainstream

Centuries later in Europe, Switzerland pioneered nickel coinage in 1850. In 1879 the Swiss adopted the 75:25 ratio called cupronickel that Belgium, the United States, and Germany used. From 1947 to 2012, most coinages in the United Kingdom were made from cupronickel (aka copper-nickel).

In part due to silver hoarding during the Civil War, the U.S. Mint began using cupronickel to circulate coinage in 3-cent pieces starting in 1865 and then for 5-cent pieces starting in 1866. Prior to these dates, both denominations had been made only in silver. Today, cupronickel makes up the cladding on either side of the United States dollar since 1971 and all quarters and dimes made after 1964. Currently, some circulating U.S. coins, such as the Jefferson nickel, are made of solid cupronickel (75:25 ratio). In the past, some early U. S. experimental pieces were also made of that same formula. However, at that time, it was called German silver and was used to make the Feuchtwanger cents of 1837, pattern U.S. cents, and half cents of 1856.

While we may never fully know the origin of the Bactrian copper-nickel coin, the ANA’s Periodic Table of Elements, available for purchase online at the Money Museum store, offers hobbyists the opportunity to learn about all the metals that make up the coins in their collections. I encourage you to purchase one and learn more about these “out of this world” metals that made it into coins from around the world.