1870 Oaxaca 20 Pesos Pattern in Lead: Value Guide

If you inherited an 1870 Mexican 20 pesos and someone told you it's a gold fortune, slow down. This particular piece is documented in lead, not gold, which puts it in a completely different category. It is uncommon, but its value depends entirely on authenticity and condition, not on any precious-metal content. Here is what it actually is and what it's worth in 2026.

What you actually have

This is a 20 pesos coin from Mexico's Decimal System, dated 1870, struck at the Casa de Moneda de Oaxaca (the Oaxaca Mint). It weighs 20.23 grams, measures 33.84 mm in diameter, and is composed of lead.

That last detail matters. A regular circulating gold 20 pesos would never be struck in lead. Lead strikes from this era are typically trial pieces, patterns, or off-metal specimens, not coins that ever spent time in someone's pocket. That makes cataloging and pricing far more specialized than for a standard-issue coin.

The 1870 date sits in the period Mexican numismatists call the República Restaurada, the restored republic under Benito Juárez after the fall of the Second Empire, which then rolled into the Porfiriato. For dating and context, see our page on the República Restaurada and Porfiriato era.

What it's worth

Here is the honest part. A one-off lead piece is not a bullion coin, so there is no melt floor to fall back on. Value comes down to three things: is it a genuine period strike, what grade is it in, and can a serious buyer verify it.

• Circulated, unverified, common wear: roughly 100 to 500 pesos (about 6 to 30 USD) if it's treated as a minor or unattributed piece.
• Certified Uncirculated (UNC) or high Mint State: several thousand pesos, potentially more if a grading service confirms it as a genuine period pattern or off-metal strike.
• Verified genuine trial/pattern piece: these can command a strong premium among specialists, but only with certification and provenance behind them.

| Coin | Year | Mint | Metal | Value range (condition dependent) | |---|---|---|---| | 20 Pesos Decimal | 1870 | Oaxaca | Lead | ~6 to 30 USD circulated, several hundred USD+ if certified genuine and high grade |

We won't invent an exact auction figure for this specific lead piece, because there is no widely published, verifiable record that fits it cleanly. A verified genuine specimen belongs in front of a specialist, not a general marketplace.

Is it rare?

The mintage for this issue is not officially documented. When there's no published production figure, it usually points to a very limited or non-standard emission rather than a mass-circulated coin. Collector forums float numbers, but none are confirmed. Treat any "only X ever made" claim as unverified until a grading service or a real auction catalog backs it up.

1870 was a single-year date for this piece, so there are no year-to-year variants to chase. There can be minor die variants (letter positioning, small striking differences) that only NGC or PCGS specialists distinguish. For a casual owner, a piece is a piece.

How to tell if yours is genuine

Start with the numbers. A real piece should weigh 20.23 grams and measure 33.84 mm. If your coin is off on either, you already have your answer.

• Weigh and measure it on a digital scale and caliper. Wrong weight or diameter is an instant red flag.
• Check the relief. Fakes tend to have flat, mushy detail. Compare the strike sharpness against reference images.
• Inspect the edge. Casting seams, file marks, or a spongy edge point to a reproduction.
• Get it graded by NGC or PCGS if the piece could be worth real money. For an unusual lead strike, third-party certification is the only thing that turns "maybe" into a sellable, verified item.

Lead is soft and easy to cast, which is exactly why a low-effort fake is plausible here. Certification is worth it before you attach any serious price to it.

Where to sell it

Your safest routes:

• A verified numismatic dealer from the Pesoteca shop directory, sorted by city, who can appraise it on the spot.
• The Pesoteca buy-and-sell forum, where collectors who understand off-metal pieces actually gather.

Before you list it anywhere, photograph the obverse, reverse, and edge, and note the exact weight. If a piece like this is genuine and certified, don't dump it to the first bidder on social media. An unusual lead strike sold blind almost always sells for a fraction of what a documented specimen brings.

Want to see how it compares to other pieces from the same date? Browse Mexican 20 pesos coins and other 1870 issues.

Think your 1870 piece might be a genuine pattern and not a copy? Post clear photos of the obverse, reverse, and edge on the Pesoteca forum and let collectors who know off-metal strikes weigh in before you set a price.

Fake, it is not gold.

Numismatic type: Balance scale.