Mexican 20 Pesos Gold 1918 (Azteca): Value & Gold Content

If you inherited or found a 1918 Mexican 20 Pesos gold coin, here is the honest answer: it is worth its gold, not a rarity premium. That gold is real money. Each piece contains 15 grams of pure gold, about 0.482 troy ounces, so in 2026 its value tracks the daily gold price plus a small premium. At current gold levels that puts a typical example roughly in the range of 900 to 1,200 USD, moving up or down with the metal.

This is the coin US dealers and collectors call the "Azteca," because the back shows the Piedra del Sol (the Aztec Sun Stone calendar). It is one of the most recognized Mexican gold coins in the world, which is good news if you want to sell: it is liquid and easy to trade almost anywhere gold is bought.

What you actually have

The 1918 20 Pesos is a bullion-grade gold coin struck at the Mexican Mint. The specs are fixed and worth memorizing before you buy or sell:

• Metal: Gold, .900 fine (90% gold, 10% copper). It is not .999 gold, despite what some listings claim. The alloy on these circulating pieces is .900.
• Total weight: 16.666 grams.
• Pure gold content: 15 grams, roughly 0.482 troy ounces. The reverse literally states it: "15 Gr. ORO PURO."
• Diameter: 27.5 mm.
• Edge: Reeded, lettered with "INDEPENDENCIA Y LIBERTAD."
• Designer: Jorge Enciso. The series ran from 1917 to 1959, with official restrikes made later.

The obverse carries the Mexican coat of arms (the eagle on a cactus), "ESTADOS UNIDOS MEXICANOS," and the year. The Sun Stone on the reverse is what earned it the Azteca nickname.

Is the 1918 date rare? No.

This is where most people get their hopes up and get it wrong. The 1918 is one of the most common dates in the whole series. The mint struck 2,831,000 pieces that year, the highest mintage of the early run. For contrast, the 1920 had only 462,000.

So a 1918 does not carry a scarcity premium. Its price is gold content, plus a modest markup because it is a trusted, instantly recognizable coin. Do not pay collector money for a common-date bullion piece, and do not expect a windfall beyond the metal.

Figures move with the daily gold price. Check the spot price the day you buy or sell.

What yours is worth

Two things set the number: the daily gold price applied to its 0.482 ounces, and condition.

• Circulated examples (visible wear) trade at close to melt value, meaning the gold price for 0.482 oz minus the dealer's margin.
• Uncirculated or high-grade examples (no wear) command a bit more, but still nowhere near a rare-coin premium.

Before any transaction, look up the current gold spot price, multiply by 0.482, and use that as your anchor. Then compare offers in the dealer directory so you are not overpaying a premium as a buyer or underselling as a seller. You can see the rest of the family in the Hidalgo gold series.

How to tell if it's genuine

Gold coins get faked, and this one is popular enough to be a target. Run these checks:

1. Weight. It must weigh 16.666 grams. A digital scale that reads to 0.01 g tells you fast. Off-weight is a red flag.
2. Diameter. It should measure 27.5 mm.
3. Magnet test. Real .900 gold is not magnetic. If it sticks to a magnet, it is not gold.
4. Edge lettering. The reeded edge should read "INDEPENDENCIA Y LIBERTAD."

If anything is off, or you just want certainty, a dealer in the directory can weigh and measure it in minutes. For a coin held for its gold, weight and diameter are the two numbers that matter most.

Where to sell it

Because of the huge mintage, this is a liquid coin. Gold buyers, coin shops, and precious-metals dealers all recognize it and will take it. Expect to be paid near its gold value (its 0.482 ounces at the day's spot) minus the dealer's margin. Get quotes from two or three places in the Pesoteca dealer directory and compare before you close. A recognized coin like this should not be sold for scrap-gold prices.

Have a 1918 20 Pesos in hand and want a read on its condition, or a quote to compare? Post clear photos of both sides in the Pesoteca forum and tell us the weight you measured.

20 pesos gold Hidalgo, 1918, Mexico City mint, Krause KM#478. A year under the constitutional presidency of Venustiano Carranza in his first term after the promulgation of the 1917 Constitution. That year the last decisive battle against the Villista remnants was fought and World War I ended in Europe on November 11, an event that directly benefited Mexico as a neutral exporter of raw materials. The 20 pesos gold officially weighs 16.666 grams with .900 fineness. Produced by mill with a round blank under the gold standard inherited from Limantour's 1905 Monetary Reform. The obverse shows the bust of Miguel Hidalgo in left profile with the legend ESTADOS UNIDOS MEXICANOS. The reverse carries the Mexican eagle on a nopal with a serpent. The assayer's signature appears on the reverse as the mark of the capital's workshop. 1918 pieces are collectible for documenting the productive start of the post-revolutionary constitutional regime and for coinciding with the end of World War I, which reorganized the world economy and benefited Mexican foreign trade of the period.