A decade ago, a funny money mystery fell into the hands of scientists and students at the Pontifical Catholic University of Peru in Lima.

The university had been acquiring 19th- and 20th-century Peruvian coins from local dealers, and graduate students in the chemistry department were analyzing the pieces for their thesis work. But one coin, a 10-cent piece known as a dinero, stood out.

The dinero was marked The problem was that official records indicated no coins of that denomination were minted in Peru that year - according to the people who made the money, the coin never existed.

Most international coin catalogs don't list 1899 dineros, said Luis Ortega, a chemist at the university. And in the rare cases that they do, there is often only a note of with no further detail, Dr. Ortega said.

Now Dr. Ortega and Fabiola Bravo Hualpa, a doctoral student, believe they have shed new light on the mystery of the coin that came from nowhere. In a paper published last year in the journal Heritage Science, they described how they subjected one of the two known 1899 dineros to a barrage of scientific analyses, illuminating its possible origins and the role it might have played during an unstable era of South American history.

To the naked eye, the 1899 coin resembles other dineros: It's silver in color and features the same coat of arms and seated woman that represents the goddess of liberty. And it's remarkably similar in size to other dineros minted around the turn of the 20th century - about the dimensions of a U.S. dime.

But when Dr. Ortega and Ms. Bravo Hualpa bombarded the 1899 coin with X-rays and measured the light it re-emitted, they determined that the dinero was largely made of copper, zinc and nickel. This alloy is known as nickel silver. It's commonly used to make silverware and ornamental objects and has a silvery appearance, but it contains no silver. Genuine dineros produced by the Lima Mint, on the other hand, are roughly 90 percent silver.

To read the complete article, see:
The Mystery of the Coin That Shouldn't Exist(https://www.nytimes.com/2024/01/07/science/dinero-peru-coin-1899-counterfeit.html)

To read earlier E-Sylum articles, see:
NEW BOOK: BAD METAL(https://www.coinbooks.org/v22/esylum_v22n31a07.html)
NEW BOOK: BAD METAL: SILVER 3 TO 25 CENTS(https://www.coinbooks.org/v25/esylum_v25n32a06.html)