This coin is in excellent shape. It was graded BU by the seller, and I think it would slab out at MS-62 or MS-63. It was also quite a splurge; I grabbed it on a whim just because it was darn pretty and the seller who displayed it had no qualms about using her bare hands to handle it. Had to save this dusky little beauty from such abuse!
The obverse shows a famous Aztec stone – the Cuauhxicalli. This monumental piece is believed to have been carved around 1479 during the reign of the 6th Aztec ruler. The Cuauhxicalli is also known as the Sun Stone, Aztec Calendar, Stone of the Five Eras, and Eagle Bowl. It is huge – at almost a 12 foot diameter, it weighs more than 24 tons. It has a similar design and pattern to other Aztec sacrificial altar decorations & may at one time have been used for holding bodies or body parts. The piece was buried shortly after the Spanish conquest, hidden under earth in the Zócalo (main square) of Mexico City. In 1760, it was unearthed and placed as a decoration in the Western tower of the metropolitan Cathedral, where it remained for 125 years. In 1885, it was transferred to the national Museum of Archaeology and History by order of the President of the Republic, General Porfirio Diaz. The Cuauhxicali takes up most of the center to the top of the obverse. Below it is the denomination “Veinte Pesos”. Below that is the legend “*15 Gr. ORO PURO*”
On the reverse, the dominant image is of an eagle feasting on a snake while perched on a prickly pear cactus. The legend reads clockwise from just before 9:00 to just after 3:00 “Estados Unidos Mexicanos”. The date is placed diagonally behind/below the eagles posterior.
Identification code: Mexico KM-478
Date: 1959* (see blow, under mintage)
Mint Mark: n/a
Mintage: Approximately 13,000 were minted in 1959. But, according to NGC, there were extensive restrikes with the old date still being used. “During 1960-1971 a total of 1,158,414 pieces were restruck, most likely dated 1959. In 1996 matte restrikes were produced. An additional 78,000 pieces dated 1959 were struck in 2000-2009”. That gives a total mintage of approximately 1,249,414 to date (with more possibly on the way).
Country of origin: Mexico
Composition: 90% gold (& 10% copper?)
Size: 27.5 mm diameter, 2 mm thick
Weight: 16.6 grams (for 15g or 0.4823 troy oz of pure gold / AGW (Actual Gold Weight))
Other details: 90% gold purity has proven a difficult sell. Many collectors prefer items with 99.9, 99.99, or 99.999% gold purity due to reduced storage & security costs. After all, a 90% gold coin also has 10% of base metal, which is “wasted” space in a storage vault or safe. The US mint had a short lived American Arts medal series in 90% gold in the 80’s, but abandoned it to focus on “purer” issues with extremely low face values. (As I write this, 20 pesos are worth approximately $1.32 US, while US bullion gold coins run from $5 to $100 face values).
One theory about why the denominations are so bizarrely low is that governments could theoretically seize the assets & redeem them only at face value. Since the 1959 peso has been demonetized (and the neuvo peso that replaced it has been demonetized too) that seems a bit odd in this case. Just something to bear in mind.
90% gold content was historically how coins were minted for most of the 19th century. Purer gold content was possible, but led to rapid wear and tear in consumers pockets. As this coin was minted long after gold coinage was in regular use, it’s gold ratio may simply be a historical nod.
Estimated Value: $625 with gold just under ~$1200/oz